diff --git a/db/migrations/20260824140000_reservation_linka_emails.sql b/db/migrations/20260824140000_reservation_linka_emails.sql
new file mode 100644
index 0000000..d42032b
--- /dev/null
+++ b/db/migrations/20260824140000_reservation_linka_emails.sql
@@ -0,0 +1,16 @@
+-- migrate:up
+
+-- The Linka Go accounts allowed to unlock the bikes for this reservation. They
+-- are plain addresses, not app users: somebody who never logs in can still be
+-- authorised, so this is not a link to `users`.
+ALTER TABLE reservations ADD COLUMN linka_emails TEXT[] NOT NULL DEFAULT '{}';
+
+-- A check constraint cannot hold a subquery, so this catches the empty string
+-- rather than any blank one. The repository trims before writing, which turns a
+-- whitespace-only address into the empty string caught here.
+ALTER TABLE reservations ADD CONSTRAINT reservations_linka_emails_filled CHECK (
+    array_position(linka_emails, NULL) IS NULL AND NOT ('' = ANY (linka_emails)));
+
+-- migrate:down
+ALTER TABLE reservations DROP CONSTRAINT reservations_linka_emails_filled;
+ALTER TABLE reservations DROP COLUMN linka_emails;
diff --git a/db/schema.sql b/db/schema.sql
index f3eac39..c182d8d 100644
--- a/db/schema.sql
+++ b/db/schema.sql
@@ -115,6 +115,8 @@ CREATE TABLE public.reservations (
     status public.reservation_status DEFAULT 'requested'::public.reservation_status NOT NULL,
     unit_id integer,
     unit_label text,
+    linka_emails text[] DEFAULT '{}'::text[] NOT NULL,
+    CONSTRAINT reservations_linka_emails_filled CHECK (((array_position(linka_emails, NULL::text) IS NULL) AND (NOT (''::text = ANY (linka_emails))))),
     CONSTRAINT reservations_telegram_handle CHECK ((telegram ~ '^@[A-Za-z][A-Za-z0-9_]{4,31}$'::text)),
     CONSTRAINT reservations_time_order CHECK ((end_time > start_time)),
     CONSTRAINT reservations_unit_label_not_blank CHECK (((unit_label IS NULL) OR (btrim(unit_label) <> ''::text))),
@@ -502,4 +504,5 @@ INSERT INTO public.schema_migrations (version) VALUES
     ('20260823170000'),
     ('20260823210000'),
     ('20260823230000'),
-    ('20260824120000');
+    ('20260824120000'),
+    ('20260824140000');
diff --git a/db/seed.sql b/db/seed.sql
index 0048f40..4d537c0 100644
--- a/db/seed.sql
+++ b/db/seed.sql
@@ -42,40 +42,48 @@ ON CONFLICT DO NOTHING;
 -- Reservations across the current week, one per status, so the admin page and
 -- the calendar always have something to show. Times are relative to `now()`.
 INSERT INTO public.reservations
-    (id, unit_id, start_time, end_time, requester_id, telegram, "description", status)
-SELECT r.id, u.id, r.start_time, r.end_time, r.requester_id, r.telegram, r."description", r.status
+    (id, unit_id, start_time, end_time, requester_id, telegram, "description", linka_emails, status)
+SELECT r.id, u.id, r.start_time, r.end_time, r.requester_id, r.telegram, r."description",
+       r.linka_emails, r.status
 FROM (VALUES
     (1, 'agepoly',
      date_trunc('day', now()) - interval '1 day' + interval '8 hours',
      date_trunc('day', now()) + interval '1 day' + interval '18 hours',
      1, '@alice_martin', 'Transport du matériel pour la rentrée',
+     ARRAY['alice.martin@epfl.ch'],
      'ongoing'::reservation_status),
     (2, 'clic',
      date_trunc('day', now()) + interval '1 day' + interval '9 hours',
      date_trunc('day', now()) + interval '2 days' + interval '17 hours',
      3, '@chloe_favre', 'Déménagement du stock de la commission',
+     ARRAY['chloe.favre@epfl.ch'],
      'approved'::reservation_status),
     (3, 'agepoly',
      date_trunc('day', now()) + interval '3 days' + interval '10 hours',
      date_trunc('day', now()) + interval '3 days' + interval '19 hours',
      2, '@bob_dupont', 'Livraison des boissons pour la soirée',
+     ARRAY['bob.dupont@epfl.ch','alice.martin@epfl.ch'],
      'requested'::reservation_status),
     (4, 'clic',
      date_trunc('day', now()) + interval '4 days' + interval '7 hours',
      date_trunc('day', now()) + interval '4 days' + interval '12 hours',
      3, '@chloe_favre', 'Récupération de matériel informatique',
+     ARRAY['chloe.favre@epfl.ch'],
      'requested'::reservation_status),
     (5, 'agepoly',
      date_trunc('day', now()) - interval '20 days' + interval '9 hours',
      date_trunc('day', now()) - interval '19 days' + interval '18 hours',
      1, '@alice_martin', 'Ancienne sortie, archivée',
+     ARRAY['alice.martin@epfl.ch'],
      'archived'::reservation_status),
     (6, 'clic',
      date_trunc('day', now()) + interval '6 days' + interval '14 hours',
      date_trunc('day', now()) + interval '6 days' + interval '18 hours',
      2, '@bob_dupont', 'Annulée faute de conducteur',
+     ARRAY['bob.dupont@epfl.ch'],
      'cancelled'::reservation_status)
-) AS r (id, unit_name, start_time, end_time, requester_id, telegram, "description", status)
+) AS r (id, unit_name, start_time, end_time, requester_id, telegram, "description",
+          linka_emails, status)
 JOIN public.units u ON u."name" = r.unit_name
 ON CONFLICT DO NOTHING;
 
diff --git a/frontend/src/components/admin/ReservationCard.vue b/frontend/src/components/admin/ReservationCard.vue
index b94794a..c24c4d8 100644
--- a/frontend/src/components/admin/ReservationCard.vue
+++ b/frontend/src/components/admin/ReservationCard.vue
@@ -109,6 +109,10 @@ function move(status: ReservationStatus) {
           {{ reservation.users.map((u) => `${u.firstname} ${u.name} <${u.email}>`).join(', ') }}
         </dd>
       </div>
+      <div v-if="reservation.linka_emails.length" class="flex gap-2">
+        <dt class="text-muted-foreground shrink-0">{{ $t('admin.reservations.linka') }}</dt>
+        <dd class="min-w-0 break-words">{{ reservation.linka_emails.join(', ') }}</dd>
+      </div>
       <div v-if="reservation.description" class="flex gap-2">
         <dt class="text-muted-foreground shrink-0">{{ $t('admin.reservations.reason') }}</dt>
         <dd class="min-w-0 break-words italic">{{ reservation.description }}</dd>
diff --git a/frontend/src/lib/api.d.ts b/frontend/src/lib/api.d.ts
index 4bd6b1e..dbd891a 100644
--- a/frontend/src/lib/api.d.ts
+++ b/frontend/src/lib/api.d.ts
@@ -438,7 +438,69 @@ export interface paths {
       }
     }
     put?: never
-    post?: never
+    /**
+     * File a reservation request
+     * @description The requester is the session user and the status starts at `requested`; neither is taken from the body.
+     */
+    post: {
+      parameters: {
+        query?: never
+        header?: never
+        path?: never
+        cookie?: never
+      }
+      requestBody: {
+        content: {
+          'application/json': components['schemas']['NewReservation']
+        }
+      }
+      responses: {
+        /** @description The reservation, as stored */
+        201: {
+          headers: {
+            [name: string]: unknown
+          }
+          content: {
+            'application/json': components['schemas']['Reservation']
+          }
+        }
+        /** @description The reservation is malformed */
+        400: {
+          headers: {
+            [name: string]: unknown
+          }
+          content?: never
+        }
+        /** @description Unauthenticated - a session is required */
+        401: {
+          headers: {
+            [name: string]: unknown
+          }
+          content?: never
+        }
+        /** @description The requester does not belong to the unit named */
+        403: {
+          headers: {
+            [name: string]: unknown
+          }
+          content?: never
+        }
+        /** @description One of the bikes is out of service */
+        409: {
+          headers: {
+            [name: string]: unknown
+          }
+          content?: never
+        }
+        /** @description The unit or one of the bikes does not exist */
+        422: {
+          headers: {
+            [name: string]: unknown
+          }
+          content?: never
+        }
+      }
+    }
     delete?: never
     options?: never
     head?: never
@@ -557,6 +619,31 @@ export interface components {
       /** @description Email of one of the `dev_users` of the configuration */
       user: string
     }
+    NewReservation: {
+      description: string
+      bikes: number[]
+      /** Format: date-time */
+      end_time: string
+      linka_emails: string[]
+      /** Format: date-time */
+      start_time: string
+      telegram: string
+      unit: components['schemas']['NewReservationUnit']
+      users: number[]
+    }
+    /** @description The same choice, as the client sends it: only the id travels for a known unit. */
+    NewReservationUnit:
+      | {
+          /** Format: int32 */
+          id: number
+          /** @constant */
+          kind: 'known'
+        }
+      | {
+          /** @constant */
+          kind: 'free'
+          name: string
+        }
     PostCallbackParams: {
       code: string
       state: string
@@ -568,6 +655,11 @@ export interface components {
       end_time: string
       /** Format: int32 */
       id: number
+      /**
+       * @description Linka Go accounts allowed to unlock the bikes. Plain addresses: they
+       *      need not belong to anybody who ever logs into this app.
+       */
+      linka_emails: string[]
       /** Format: int32 */
       requester: number
       /** Format: date-time */
diff --git a/frontend/src/locales/en.yml b/frontend/src/locales/en.yml
index 922e6ba..1a8e77c 100644
--- a/frontend/src/locales/en.yml
+++ b/frontend/src/locales/en.yml
@@ -52,7 +52,9 @@ reservation:
   error-telegram: "Invalid Telegram username (example: {'@'}my_username)."
   error-email: One of the email addresses is invalid.
   error-form: The form contains errors.
-  not-implemented: Submitting is not wired to the backend yet.
+  submitted: Request sent. It will show up in the pending requests.
+  submitting: Sending…
+  submit-error: Could not send the request.
 login:
   title: Log in
   intro: Log in with your AGEPoly account to book a cargobike.
@@ -96,6 +98,7 @@ admin:
     bikes: Cargobike(s)
     telegram: Telegram
     people: People
+    linka: Linka Go accounts
     reason: Reason
     load-error: Unable to load the reservations.
     error: The status change failed.
diff --git a/frontend/src/locales/fr.yml b/frontend/src/locales/fr.yml
index 1fca4b6..a70412a 100644
--- a/frontend/src/locales/fr.yml
+++ b/frontend/src/locales/fr.yml
@@ -53,7 +53,9 @@ reservation:
   error-telegram: "Username Telegram invalide (exemple : {'@'}mon_username)."
   error-email: Une des adresses e-mail est invalide.
   error-form: Le formulaire contient des erreurs.
-  not-implemented: L'envoi n'est pas encore branché sur le backend.
+  submitted: Demande envoyée. Elle apparaîtra dans les demandes en attente.
+  submitting: Envoi…
+  submit-error: L'envoi de la demande a échoué.
 login:
   title: Connexion
   intro: Connectez-vous avec votre compte AGEPoly pour réserver un cargobike.
@@ -97,6 +99,7 @@ admin:
     bikes: Cargobike(s)
     telegram: Telegram
     people: Personnes
+    linka: Comptes Linka Go
     reason: Raison
     load-error: Impossible de charger les réservations.
     error: Le changement de statut a échoué.
diff --git a/frontend/src/services/api/reservations.ts b/frontend/src/services/api/reservations.ts
index cf7c0c0..b7bd8bb 100644
--- a/frontend/src/services/api/reservations.ts
+++ b/frontend/src/services/api/reservations.ts
@@ -1,11 +1,11 @@
 /**
- * Reservations, from the administration side. Reading the whole list is an
- * admin action, so these hooks are only ever mounted on /admin.
+ * Reservations. Filing a request only needs a session; reading the whole list is
+ * an admin action, so `useReservations` is only ever mounted on /admin.
  */
 import { useMutation, useQuery, useQueryClient } from '@tanstack/vue-query'
 import { HttpStatus } from 'http-status-ts'
 
-import type { Reservation, ReservationStatus } from '@/utils/types'
+import type { NewReservation, Reservation, ReservationStatus } from '@/utils/types'
 import { getClient } from './client'
 
 export const RESERVATIONS_KEY = ['reservations']
@@ -47,3 +47,27 @@ export function useSetReservationStatus() {
     },
   })
 }
+
+/**
+ * Files a request. The backend fills in the requester and the `requested`
+ * status, so neither is part of the body.
+ */
+export function useCreateReservation() {
+  const queryClient = useQueryClient()
+  return useMutation({
+    retry: 0,
+    mutationFn: async (reservation: NewReservation) => {
+      const { data, response, error } = await getClient().POST('/api/reservations', {
+        body: reservation,
+      })
+      if (response.status !== HttpStatus.CREATED) {
+        // The handler answers with a plain string, which is what to show
+        throw new Error(typeof error === 'string' ? error : `Unexpected status: ${response.status}`)
+      }
+      return data as Reservation
+    },
+    // The admin list is a different query: let it refetch rather than guessing
+    // where the new reservation belongs in its ordering.
+    onSuccess: () => queryClient.invalidateQueries({ queryKey: RESERVATIONS_KEY }),
+  })
+}
diff --git a/frontend/src/utils/types.ts b/frontend/src/utils/types.ts
index a8a3840..4557f5d 100644
--- a/frontend/src/utils/types.ts
+++ b/frontend/src/utils/types.ts
@@ -27,6 +27,7 @@ export type Reservation = components['schemas']['Reservation']
 export type ReservationStatus = components['schemas']['ReservationStatus']
 export type UserSummary = components['schemas']['UserSummary']
 export type ReservationUnit = components['schemas']['ReservationUnit']
+export type NewReservation = components['schemas']['NewReservation']
 
 /**
  * What to display for a reservation's unit: the name of the unit it points at,
diff --git a/frontend/src/views/ReservationView.vue b/frontend/src/views/ReservationView.vue
index a38f9c6..1a92c1c 100644
--- a/frontend/src/views/ReservationView.vue
+++ b/frontend/src/views/ReservationView.vue
@@ -16,8 +16,9 @@ import { Label } from '@/components/ui/label'
 import { Skeleton } from '@/components/ui/skeleton'
 import { Textarea } from '@/components/ui/textarea'
 import { useBikes } from '@/services/api/bikes'
+import { useCreateReservation } from '@/services/api/reservations'
 import { useSession } from '@/services/api/auth'
-import type { Bike } from '@/utils/types'
+import type { Bike, NewReservation } from '@/utils/types'
 
 const { t } = useI18n()
 
@@ -156,6 +157,27 @@ function reset() {
   submitted.value = false
 }
 
+const create = useCreateReservation()
+
+/** The form, as the api wants it. Both are non-null once `validate()` passed. */
+function payload(): NewReservation {
+  const association = form.association!
+  return {
+    unit:
+      association.kind === 'known'
+        ? { kind: 'known', id: association.id }
+        : { kind: 'free', name: association.name.trim() },
+    start_time: start.value!.toISOString(),
+    end_time: end.value!.toISOString(),
+    // The backend adds the requester itself; nobody else is picked here yet
+    users: [],
+    telegram: `@${form.telegram}`,
+    description: form.reason.trim(),
+    bikes: [...form.bikes],
+    linka_emails: form.emails.map((email) => email.trim()).filter(Boolean),
+  }
+}
+
 function submit() {
   submitted.value = true
   if (!validate()) {
@@ -163,9 +185,15 @@ function submit() {
     return
   }
 
-  // TODO: replace with a `useCreateReservation` mutation once
-  // `POST /api/reservations` exists.
-  toast.info(t('reservation.not-implemented'))
+  create.mutate(payload(), {
+    onSuccess: () => {
+      toast.success(t('reservation.submitted'))
+      reset()
+    },
+    // The message is the backend's own: "bike 3 is out of service" is worth
+    // reading, and a generic failure would hide it.
+    onError: (error) => toast.error(error.message || t('reservation.submit-error')),
+  })
 }
 </script>
 
@@ -370,8 +398,15 @@ function submit() {
 
           <!-- Actions -->
           <div class="flex flex-wrap gap-2">
-            <Button type="submit">{{ $t('reservation.submit') }}</Button>
-            <Button type="button" variant="outline" @click="reset()">
+            <Button type="submit" :disabled="create.isPending.value">
+              {{ create.isPending.value ? $t('reservation.submitting') : $t('reservation.submit') }}
+            </Button>
+            <Button
+              type="button"
+              variant="outline"
+              :disabled="create.isPending.value"
+              @click="reset()"
+            >
               {{ $t('reservation.reset') }}
             </Button>
           </div>
diff --git a/src/api/bikes.rs b/src/api/bikes.rs
index 2cc4dae..908ecc3 100644
--- a/src/api/bikes.rs
+++ b/src/api/bikes.rs
@@ -41,9 +41,7 @@ async fn set_status(
 ) -> Result<(), (StatusCode, String)> {
     match admin(ac)?.set_bike_status(id, status).await {
         Ok(()) => Ok(()),
-        Err(err) if err.is_not_found() => {
-            Err((StatusCode::NOT_FOUND, "No such bike".to_owned()))
-        }
+        Err(err) if err.is_not_found() => Err((StatusCode::NOT_FOUND, "No such bike".to_owned())),
         Err(err) => unexpected_error("set_bike_status", err),
     }
 }
diff --git a/src/api/helpers.rs b/src/api/helpers.rs
index f0d4270..f070143 100644
--- a/src/api/helpers.rs
+++ b/src/api/helpers.rs
@@ -1,7 +1,7 @@
 use aide::transform::TransformResponse;
+use axum::http::StatusCode;
 use schemars::JsonSchema;
 use serde::Deserialize;
-use axum::http::StatusCode;
 use tracing::error;
 
 use crate::core::{
diff --git a/src/api/reservations.rs b/src/api/reservations.rs
index e1882b0..3a412bb 100644
--- a/src/api/reservations.rs
+++ b/src/api/reservations.rs
@@ -1,6 +1,7 @@
-//! Reservations, from the administration side.
+//! Reservations.
 //!
-//! Reading the whole list is an admin action for now; changing a status is
+//! Filing a request only needs a session — the requester is taken from it, never
+//! from the body. Reading the whole list is an admin action for now; changing a status is
 //! reserved to the unit the reservation belongs to (an admin manages every
 //! unit), which is why the handler resolves the unit before narrowing the
 //! controller down.
@@ -12,25 +13,25 @@ use aide::{
     },
     transform::TransformOperation,
 };
-use axum::{
-    Json,
-    extract::Path,
-    http::StatusCode,
-};
+use axum::{Json, extract::Path, http::StatusCode};
 use schemars::JsonSchema;
 use serde::Deserialize;
 
 use crate::{
-    api::helpers::{IdPath, admin, admin_desc, manager, manager_desc, unexpected_error},
+    api::helpers::{IdPath, admin, admin_desc, desc, manager, manager_desc, unexpected_error},
     core::{
         controller::{AppController, ControllerError, reservations::ReservationsControllerError},
-        models::reservation::{Reservation, ReservationStatus},
+        models::reservation::{NewReservation, Reservation, ReservationStatus},
     },
 };
 
 pub fn routes() -> ApiRouter {
     ApiRouter::new()
-        .api_route("/", get_with(get_reservations, get_reservations_docs))
+        .api_route(
+            "/",
+            get_with(get_reservations, get_reservations_docs)
+                .post_with(create_reservation, create_reservation_docs),
+        )
         .api_route("/{id}/status", put_with(set_status, set_status_docs))
 }
 
@@ -50,6 +51,47 @@ fn get_reservations_docs(op: TransformOperation) -> TransformOperation {
         .response_with::<403, (), _>(admin_desc)
 }
 
+/// Files a request. The reservation always starts in `requested`: the status is
+/// not part of the body, so a requester cannot approve their own booking.
+#[axum::debug_handler]
+async fn create_reservation(
+    ac: AppController,
+    Json(reservation): Json<NewReservation>,
+) -> Result<(StatusCode, Json<Reservation>), (StatusCode, String)> {
+    match ac.create_reservation(reservation).await {
+        Ok(reservation) => Ok((StatusCode::CREATED, Json(reservation))),
+        Err(ControllerError::Reservation(
+            err @ ReservationsControllerError::ReservationInvalid,
+        )) => Err((StatusCode::BAD_REQUEST, err.to_string())),
+        Err(ControllerError::Reservation(
+            err @ ReservationsControllerError::BikeOutOfService(_),
+        )) => Err((StatusCode::CONFLICT, err.to_string())),
+        Err(ControllerError::Reservation(
+            err @ ReservationsControllerError::NotAMemberOfUnit(_),
+        )) => Err((StatusCode::FORBIDDEN, err.to_string())),
+        // An unknown unit id or bike id: the client named something that is gone
+        Err(err) if err.is_not_found() => Err((
+            StatusCode::UNPROCESSABLE_ENTITY,
+            "Unknown unit or bike".to_owned(),
+        )),
+        Err(err) => unexpected_error("create_reservation", err),
+    }
+}
+
+fn create_reservation_docs(op: TransformOperation) -> TransformOperation {
+    op.tag("Reservations")
+        .summary("File a reservation request")
+        .description(
+            "The requester is the session user and the status starts at `requested`; \
+             neither is taken from the body.",
+        )
+        .response_with::<201, Json<Reservation>, _>(desc("The reservation, as stored"))
+        .response_with::<400, (), _>(desc("The reservation is malformed"))
+        .response_with::<403, (), _>(desc("The requester does not belong to the unit named"))
+        .response_with::<409, (), _>(desc("One of the bikes is out of service"))
+        .response_with::<422, (), _>(desc("The unit or one of the bikes does not exist"))
+}
+
 #[derive(Debug, Deserialize, JsonSchema)]
 struct SetStatusForm {
     status: ReservationStatus,
@@ -75,9 +117,9 @@ async fn set_status(
         .await
     {
         Ok(()) => Ok(()),
-        Err(ControllerError::Reservation(err @ ReservationsControllerError::InvalidTransition(..))) => {
-            Err((StatusCode::CONFLICT, err.to_string()))
-        }
+        Err(ControllerError::Reservation(
+            err @ ReservationsControllerError::InvalidTransition(..),
+        )) => Err((StatusCode::CONFLICT, err.to_string())),
         Err(err) => unexpected_error("set_status", err),
     }
 }
@@ -85,9 +127,7 @@ async fn set_status(
 fn set_status_docs(op: TransformOperation) -> TransformOperation {
     op.tag("Reservations")
         .summary("Move a reservation through its state machine")
-        .description(
-            "Refuses a transition the state machine does not allow, with a 409.",
-        )
+        .description("Refuses a transition the state machine does not allow, with a 409.")
         .response_with::<403, (), _>(manager_desc)
         .response::<404, ()>()
         .response::<409, ()>()
diff --git a/src/core/controller/authn.rs b/src/core/controller/authn.rs
index ca30590..176cc88 100644
--- a/src/core/controller/authn.rs
+++ b/src/core/controller/authn.rs
@@ -76,9 +76,7 @@ impl AnonAppController {
                 self.db.save_whiskey_data(authorize_backend_data).await?;
                 Ok(redirect_to)
             }
-            Err(WhiskeyError::ProtocolError) => {
-                Err(AuthnControllerError::OIDCProtocolError.into())
-            }
+            Err(WhiskeyError::ProtocolError) => Err(AuthnControllerError::OIDCProtocolError.into()),
             Err(WhiskeyError::InternalError) => Err(ControllerError::InternalError(
                 "Originated from Whiskey".to_owned(),
             )),
@@ -93,16 +91,18 @@ impl AnonAppController {
         state: String,
     ) -> Result<User, ControllerError> {
         // Consumes the state: a callback can never be replayed
-        let backend_data = self.db.take_whiskey_data(state.clone()).await.map_err(|_| {
-            debug!("unknown, already used or expired oidc state");
-            AuthnControllerError::OIDCProtocolError
-        })?;
+        let backend_data = self
+            .db
+            .take_whiskey_data(state.clone())
+            .await
+            .map_err(|_| {
+                debug!("unknown, already used or expired oidc state");
+                AuthnControllerError::OIDCProtocolError
+            })?;
 
         match callback(code, state, backend_data).await {
             Ok(user_info) => self.upsert_oidc_user(user_info).await,
-            Err(WhiskeyError::ProtocolError) => {
-                Err(AuthnControllerError::OIDCProtocolError.into())
-            }
+            Err(WhiskeyError::ProtocolError) => Err(AuthnControllerError::OIDCProtocolError.into()),
             Err(WhiskeyError::InternalError) => Err(ControllerError::InternalError(
                 "originated from Whiskey".to_owned(),
             )),
diff --git a/src/core/controller/bikes.rs b/src/core/controller/bikes.rs
index 3eb046c..04b5218 100644
--- a/src/core/controller/bikes.rs
+++ b/src/core/controller/bikes.rs
@@ -15,7 +15,6 @@ impl AnonAppController {
     pub async fn get_bike(&self, id: BikeId) -> Result<Bike, ControllerError> {
         self.db.get_bike(id).await.map_err(Into::into)
     }
-
 }
 
 /// Changing the fleet is an admin action
diff --git a/src/core/controller/reservations.rs b/src/core/controller/reservations.rs
index 19882a9..0f41ac0 100644
--- a/src/core/controller/reservations.rs
+++ b/src/core/controller/reservations.rs
@@ -5,10 +5,12 @@ use crate::core::{
     models::{
         bike::BikeStatus,
         reservation::{
-            NewReservation, Reservation, ReservationEdit, ReservationId, ReservationStatus,
+            NewReservation, NewReservationUnit, Reservation, ReservationEdit, ReservationId,
+            ReservationStatus,
         },
         unit::UnitId,
     },
+    repositories::RepositoryError,
 };
 
 /// Reading the reservations needs no session: the calendar is public.
@@ -30,7 +32,6 @@ impl AnonAppController {
     pub async fn get_reservation(&self, id: ReservationId) -> Result<Reservation, ControllerError> {
         self.db.get_reservation(id).await.map_err(Into::into)
     }
-
 }
 
 /// Filing a request is done in one's own name: the requester is the session
@@ -43,6 +44,20 @@ impl AppController {
         if !reservation.is_valid() {
             return Err(ReservationsControllerError::ReservationInvalid.into());
         }
+        // Naming a known unit means claiming to act for it. An admin may file
+        // for any unit, but it still has to exist: without this the foreign key
+        // would be what rejects the insert, and that surfaces as a 500.
+        if let NewReservationUnit::Known { id } = reservation.unit {
+            let user = self.user();
+            if !user.units.iter().any(|unit| unit.id == id) {
+                if !user.admin {
+                    return Err(ReservationsControllerError::NotAMemberOfUnit(id).into());
+                }
+                if !self.db.get_units().await?.iter().any(|unit| unit.id == id) {
+                    return Err(RepositoryError::NotFound(format!("unit {id}")).into());
+                }
+            }
+        }
         // A bike out of service cannot be booked
         for id in &reservation.bikes {
             if self.get_bike(*id).await?.status == BikeStatus::OutOfService {
@@ -120,4 +135,6 @@ pub enum ReservationsControllerError {
     ReservationFinal(ReservationStatus),
     #[error("Bike {0} is out of service and cannot be booked")]
     BikeOutOfService(i32),
+    #[error("The requester does not belong to unit {0}")]
+    NotAMemberOfUnit(UnitId),
 }
diff --git a/src/core/controller/users.rs b/src/core/controller/users.rs
index 594599c..28b0300 100644
--- a/src/core/controller/users.rs
+++ b/src/core/controller/users.rs
@@ -21,7 +21,6 @@ impl AnonAppController {
             .await
             .map_err(Into::into)
     }
-
 }
 
 impl AdminAppController {
diff --git a/src/core/models/reservation.rs b/src/core/models/reservation.rs
index 9a1645b..c617ae5 100644
--- a/src/core/models/reservation.rs
+++ b/src/core/models/reservation.rs
@@ -43,7 +43,6 @@ impl ReservationStatus {
     }
 }
 
-
 /// The unit a reservation is filed for.
 ///
 /// Either one we know — a Whiskey group, with its row — or a plain name the
@@ -107,6 +106,9 @@ pub struct Reservation {
     pub telegram: String,
     pub description: String,
     pub bikes: Vec<BikeId>,
+    /// Linka Go accounts allowed to unlock the bikes. Plain addresses: they
+    /// need not belong to anybody who ever logs into this app.
+    pub linka_emails: Vec<String>,
     pub status: ReservationStatus,
 }
 
@@ -119,6 +121,7 @@ pub struct NewReservation {
     pub telegram: String,
     pub description: String,
     pub bikes: Vec<BikeId>,
+    pub linka_emails: Vec<String>,
 }
 
 #[derive(Debug, Serialize, Deserialize, Clone, JsonSchema, PartialEq, Eq)]
@@ -131,11 +134,36 @@ pub struct ReservationEdit {
     pub telegram: String,
     pub description: String,
     pub bikes: Vec<BikeId>,
+    pub linka_emails: Vec<String>,
+}
+
+/// At least one address, none of them blank: a reservation nobody can unlock
+/// is of no use to the admin who has to authorise it.
+fn linka_emails_valid(emails: &[String]) -> bool {
+    !emails.is_empty() && emails.iter().all(|email| !email.trim().is_empty())
+}
+
+/// Mirrors the `reservations_telegram_handle` check constraint. Duplicated on
+/// purpose: without it a bad handle only fails once it reaches postgres, which
+/// surfaces as a 500 instead of "your handle is malformed".
+fn telegram_valid(handle: &str) -> bool {
+    let Some(rest) = handle.strip_prefix('@') else {
+        return false;
+    };
+    let mut chars = rest.chars();
+    if !matches!(chars.next(), Some(c) if c.is_ascii_alphabetic()) {
+        return false;
+    }
+    (5..=32).contains(&rest.len()) && rest.chars().all(|c| c.is_ascii_alphanumeric() || c == '_')
 }
 
 impl NewReservation {
     pub fn is_valid(&self) -> bool {
-        self.unit.is_valid() && self.end_time > self.start_time && !self.bikes.is_empty()
+        self.unit.is_valid()
+            && self.end_time > self.start_time
+            && !self.bikes.is_empty()
+            && telegram_valid(&self.telegram)
+            && linka_emails_valid(&self.linka_emails)
     }
 }
 
@@ -145,5 +173,41 @@ impl ReservationEdit {
             && self.end_time > self.start_time
             && !self.bikes.is_empty()
             && !self.users.is_empty()
+            && telegram_valid(&self.telegram)
+            && linka_emails_valid(&self.linka_emails)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn telegram_handles_match_the_database_constraint() {
+        assert!(telegram_valid("@milan_hyenne"));
+        assert!(telegram_valid("@abcde"));
+        assert!(telegram_valid(&format!("@a{}", "b".repeat(31))));
+
+        assert!(!telegram_valid("milan_hyenne"), "missing @");
+        assert!(!telegram_valid("@abcd"), "too short");
+        assert!(
+            !telegram_valid(&format!("@a{}", "b".repeat(32))),
+            "too long"
+        );
+        assert!(!telegram_valid("@1abcde"), "must start with a letter");
+        assert!(!telegram_valid("@abc-de"), "no dash");
+        assert!(!telegram_valid("@"), "nothing after the @");
+        assert!(
+            !telegram_valid("@élodie"),
+            "ascii only, as in the constraint"
+        );
+    }
+
+    #[test]
+    fn linka_emails_must_hold_at_least_one_filled_address() {
+        assert!(linka_emails_valid(&["a@b.ch".to_owned()]));
+        assert!(!linka_emails_valid(&[]));
+        assert!(!linka_emails_valid(&["   ".to_owned()]));
+        assert!(!linka_emails_valid(&["a@b.ch".to_owned(), "".to_owned()]));
     }
 }
diff --git a/src/core/repositories/users_repository.rs b/src/core/repositories/users_repository.rs
index d049e90..3e3d40a 100644
--- a/src/core/repositories/users_repository.rs
+++ b/src/core/repositories/users_repository.rs
@@ -21,8 +21,7 @@ pub trait UsersRepository {
     async fn upsert_user(&self, user: NewUser) -> Result<User, RepositoryError>;
 
     /// Replaces the whole set of units the user belongs to
-    async fn set_user_units(&self, id: UserId, units: Vec<UnitId>)
-    -> Result<(), RepositoryError>;
+    async fn set_user_units(&self, id: UserId, units: Vec<UnitId>) -> Result<(), RepositoryError>;
 
     async fn set_user_admin(&self, id: UserId, admin: bool) -> Result<(), RepositoryError>;
 }
diff --git a/src/main.rs b/src/main.rs
index e0d6c39..e639032 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -37,12 +37,9 @@ async fn main() {
     // Anything that is not an api route is served from the built frontend,
     // falling back on index.html so the vue router can handle the path.
     // (`fallback` and not `not_found_service`, which would force a 404 status)
-    let app = api::get_router(aac).fallback_service(
-        ServeDir::new(&config.frontend_dir).fallback(ServeFile::new(format!(
-            "{}/index.html",
-            config.frontend_dir
-        ))),
-    );
+    let app = api::get_router(aac).fallback_service(ServeDir::new(&config.frontend_dir).fallback(
+        ServeFile::new(format!("{}/index.html", config.frontend_dir)),
+    ));
 
     let bind_address = config.get_bind_address();
     let listener = tokio::net::TcpListener::bind(&bind_address).await.unwrap();
diff --git a/src/services/database/reservations.rs b/src/services/database/reservations.rs
index 4048527..edc1dae 100644
--- a/src/services/database/reservations.rs
+++ b/src/services/database/reservations.rs
@@ -71,6 +71,7 @@ struct ReservationDB {
     pub telegram: String,
     pub description: String,
     pub status: ReservationStatusDB,
+    pub linka_emails: Vec<String>,
     pub users: Value,
     pub bikes: Vec<i32>,
 }
@@ -100,6 +101,7 @@ impl TryFrom<ReservationDB> for Reservation {
             telegram: value.telegram,
             description: value.description,
             bikes: value.bikes,
+            linka_emails: value.linka_emails,
             status: value.status.into(),
         })
     }
@@ -155,6 +157,13 @@ fn split_unit(unit: &NewReservationUnit) -> (Option<i32>, Option<String>) {
     }
 }
 
+/// Surrounding spaces never belong to an address, and trimming is what turns a
+/// whitespace-only one into the empty string the `reservations_linka_emails_filled`
+/// check rejects.
+fn trim_emails(emails: &[String]) -> Vec<String> {
+    emails.iter().map(|email| email.trim().to_owned()).collect()
+}
+
 #[async_trait]
 impl ReservationsRepository for SqlxDatabase {
     async fn get_reservations(&self) -> Result<Vec<Reservation>, RepositoryError> {
@@ -172,6 +181,7 @@ impl ReservationsRepository for SqlxDatabase {
                 r.requester_id,
                 r.telegram,
                 r."description",
+                r.linka_emails,
                 r.status AS "status: ReservationStatusDB",
                 COALESCE((
                     SELECT json_agg(json_build_object(
@@ -217,6 +227,7 @@ impl ReservationsRepository for SqlxDatabase {
                 r.requester_id,
                 r.telegram,
                 r."description",
+                r.linka_emails,
                 r.status AS "status: ReservationStatusDB",
                 COALESCE((
                     SELECT json_agg(json_build_object(
@@ -261,6 +272,7 @@ impl ReservationsRepository for SqlxDatabase {
                 r.requester_id,
                 r.telegram,
                 r."description",
+                r.linka_emails,
                 r.status AS "status: ReservationStatusDB",
                 COALESCE((
                     SELECT json_agg(json_build_object(
@@ -297,10 +309,12 @@ impl ReservationsRepository for SqlxDatabase {
         // No status here: the column defaults to 'requested', the start of the
         // state machine.
         let (unit_id, unit_label) = split_unit(&reservation.unit);
+        let linka_emails = trim_emails(&reservation.linka_emails);
         let id = query!(
             r#"INSERT INTO reservations
-                (unit_id, unit_label, start_time, end_time, requester_id, telegram, "description")
-                VALUES ($1, $2, $3, $4, $5, $6, $7)
+                (unit_id, unit_label, start_time, end_time, requester_id, telegram,
+                 "description", linka_emails)
+                VALUES ($1, $2, $3, $4, $5, $6, $7, $8)
                 RETURNING id"#,
             unit_id,
             unit_label,
@@ -308,7 +322,8 @@ impl ReservationsRepository for SqlxDatabase {
             reservation.end_time,
             requester,
             reservation.telegram,
-            reservation.description
+            reservation.description,
+            &linka_emails
         )
         .fetch_one(&mut *tx)
         .await?
@@ -336,10 +351,11 @@ impl ReservationsRepository for SqlxDatabase {
         let mut tx = self.pool.begin().await?;
 
         let (unit_id, unit_label) = split_unit(&reservation.unit);
+        let linka_emails = trim_emails(&reservation.linka_emails);
         let result = query!(
             r#"UPDATE reservations
             SET unit_id = $2, unit_label = $3, start_time = $4, end_time = $5,
-                telegram = $6, "description" = $7
+                telegram = $6, "description" = $7, linka_emails = $8
             WHERE id = $1"#,
             reservation.id,
             unit_id,
@@ -347,7 +363,8 @@ impl ReservationsRepository for SqlxDatabase {
             reservation.start_time,
             reservation.end_time,
             reservation.telegram,
-            reservation.description
+            reservation.description,
+            &linka_emails
         )
         .execute(&mut *tx)
         .await?;
diff --git a/src/utils/whiskey.rs b/src/utils/whiskey.rs
index 064c989..47516bf 100644
--- a/src/utils/whiskey.rs
+++ b/src/utils/whiskey.rs
@@ -55,9 +55,7 @@ async fn get_client() -> &'static Client {
                 ClientId::new(config.oidc.client_id),
                 Some(ClientSecret::new(config.oidc.client_secret)),
             )
-            .set_redirect_uri(
-                RedirectUrl::new(redirect_url).unwrap(),
-            )
+            .set_redirect_uri(RedirectUrl::new(redirect_url).unwrap())
         })
         .await
 }
@@ -247,12 +245,11 @@ async fn groups_from_userinfo(
         }
     };
 
-    match request
-        .request_async(get_http_client())
-        .await
-        .map(|claims: openidconnect::UserInfoClaims<WhiskeyClaims, CoreGenderClaim>| {
+    match request.request_async(get_http_client()).await.map(
+        |claims: openidconnect::UserInfoClaims<WhiskeyClaims, CoreGenderClaim>| {
             claims.additional_claims().groups.clone()
-        }) {
+        },
+    ) {
         Ok(groups) => groups,
         Err(err) => {
             debug!("userinfo request failed: {err:?}");