diff --git a/crates/api/src/admin_authorities.rs b/crates/api/src/admin_authorities.rs
index 22e1e45..deba5f1 100644
--- a/crates/api/src/admin_authorities.rs
+++ b/crates/api/src/admin_authorities.rs
@@ -3,18 +3,19 @@
 use auth::{Authorized, EditCatalogue, ViewInternal};
 use axum::{
     Json, Router,
-    extract::{Query, State},
+    extract::{Path, Query, State},
     http::StatusCode,
+    response::{IntoResponse, Response},
     routing::get,
 };
-use domain::{AuditActor, AuthorityKind, LocalizedLabel, NewAuthority};
+use domain::{AuditActor, AuthorityId, AuthorityKind, LocalizedLabel, NewAuthority};
 use serde::{Deserialize, Serialize};
 use utoipa::ToSchema;
 
 use crate::{
     AppState,
     admin_objects::LabelView,
-    admin_vocab::{CreatedId, LabelInput},
+    admin_vocab::{CreatedId, InUseView, LabelInput},
 };
 
 #[derive(Serialize, ToSchema)]
@@ -129,9 +130,125 @@ pub(crate) async fn create_authority(
     Ok((StatusCode::CREATED, Json(CreatedId { id: id.to_string() })))
 }
 
-pub(crate) fn routes() -> Router<AppState> {
-    Router::new().route(
-        "/api/admin/authorities",
-        get(list_authorities).post(create_authority),
-    )
+#[derive(Deserialize, ToSchema)]
+pub(crate) struct UpdateAuthorityRequest {
+    pub external_uri: Option<String>,
+    pub labels: Vec<LabelInput>,
+}
+
+#[utoipa::path(
+    patch, path = "/api/admin/authorities/{id}",
+    request_body = UpdateAuthorityRequest,
+    params(("id" = String, Path, description = "Authority id (UUID)")),
+    responses(
+        (status = 204),
+        (status = 401),
+        (status = 403),
+        (status = 404)
+    )
+)]
+pub(crate) async fn update_authority(
+    auth: Authorized<EditCatalogue>,
+    State(state): State<AppState>,
+    Path(id): Path<String>,
+    Json(req): Json<UpdateAuthorityRequest>,
+) -> Result<StatusCode, StatusCode> {
+    let id = id
+        .parse::<AuthorityId>()
+        .map_err(|_| StatusCode::NOT_FOUND)?;
+
+    let labels: Vec<LocalizedLabel> = req
+        .labels
+        .into_iter()
+        .map(|l| LocalizedLabel {
+            lang: l.lang,
+            label: l.label,
+        })
+        .collect();
+
+    let mut tx = state
+        .db
+        .pool()
+        .begin()
+        .await
+        .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+
+    let existed = db::authority::update_authority(
+        &mut tx,
+        AuditActor::User(auth.user.id.to_uuid()),
+        id,
+        req.external_uri.as_deref(),
+        &labels,
+    )
+    .await
+    .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+
+    if existed {
+        tx.commit()
+            .await
+            .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+
+        Ok(StatusCode::NO_CONTENT)
+    } else {
+        let _ = tx.rollback().await;
+
+        Err(StatusCode::NOT_FOUND)
+    }
+}
+
+#[utoipa::path(
+    delete, path = "/api/admin/authorities/{id}",
+    params(("id" = String, Path, description = "Authority id (UUID)")),
+    responses(
+        (status = 204),
+        (status = 401),
+        (status = 403),
+        (status = 404),
+        (status = 409, body = InUseView, description = "Referenced by catalogue objects")
+    )
+)]
+pub(crate) async fn delete_authority(
+    auth: Authorized<EditCatalogue>,
+    State(state): State<AppState>,
+    Path(id): Path<String>,
+) -> Response {
+    let Ok(id) = id.parse::<AuthorityId>() else {
+        return StatusCode::NOT_FOUND.into_response();
+    };
+
+    let Ok(mut tx) = state.db.pool().begin().await else {
+        return StatusCode::INTERNAL_SERVER_ERROR.into_response();
+    };
+
+    match db::authority::delete_authority(&mut tx, AuditActor::User(auth.user.id.to_uuid()), id)
+        .await
+    {
+        Ok(db::DeleteOutcome::Deleted) => match tx.commit().await {
+            Ok(()) => StatusCode::NO_CONTENT.into_response(),
+            Err(_) => StatusCode::INTERNAL_SERVER_ERROR.into_response(),
+        },
+        Ok(db::DeleteOutcome::InUse { count }) => {
+            let _ = tx.rollback().await;
+
+            (StatusCode::CONFLICT, Json(InUseView { count })).into_response()
+        }
+        Ok(db::DeleteOutcome::NotFound) => {
+            let _ = tx.rollback().await;
+
+            StatusCode::NOT_FOUND.into_response()
+        }
+        Err(_) => StatusCode::INTERNAL_SERVER_ERROR.into_response(),
+    }
+}
+
+pub(crate) fn routes() -> Router<AppState> {
+    Router::new()
+        .route(
+            "/api/admin/authorities",
+            get(list_authorities).post(create_authority),
+        )
+        .route(
+            "/api/admin/authorities/{id}",
+            axum::routing::patch(update_authority).delete(delete_authority),
+        )
 }
diff --git a/crates/api/src/openapi.rs b/crates/api/src/openapi.rs
index 1484363..7c7383a 100644
--- a/crates/api/src/openapi.rs
+++ b/crates/api/src/openapi.rs
@@ -37,7 +37,9 @@ use crate::{
         admin_vocab::delete_vocabulary,
         admin_search::search_objects,
         admin_authorities::list_authorities,
-        admin_authorities::create_authority
+        admin_authorities::create_authority,
+        admin_authorities::update_authority,
+        admin_authorities::delete_authority
     ),
     components(schemas(
         config::ConfigView,
@@ -71,6 +73,7 @@ use crate::{
         admin_search::SearchResultsView,
         admin_authorities::AuthorityView,
         admin_authorities::NewAuthorityRequest,
+        admin_authorities::UpdateAuthorityRequest,
         domain::Visibility,
         domain::AuthorityKind,
         domain::DataType
diff --git a/crates/api/tests/admin_catalog.rs b/crates/api/tests/admin_catalog.rs
index 4f9d05a..5157c31 100644
--- a/crates/api/tests/admin_catalog.rs
+++ b/crates/api/tests/admin_catalog.rs
@@ -587,3 +587,130 @@ async fn delete_vocabulary_with_terms_is_409(pool: PgPool) {
         serde_json::from_slice(&blocked.into_body().collect().await.unwrap().to_bytes()).unwrap();
     assert_eq!(body["count"], 1);
 }
+
+#[sqlx::test(migrations = "../db/migrations")]
+async fn delete_authority_referenced_is_409(pool: PgPool) {
+    migrate_sessions(&db::Db::from_pool(pool.clone()))
+        .await
+        .unwrap();
+
+    seed_user(&pool, "ed@example.com", "pw-editor-123", Role::Editor).await;
+
+    let app = build_app(state(pool));
+    let cookie = login(&app, "ed@example.com", "pw-editor-123").await;
+
+    // create an authority
+    let a = send(
+        &app,
+        &cookie,
+        "POST",
+        "/api/admin/authorities",
+        Some(r#"{"kind":"person","external_uri":null,"labels":[{"lang":"sv","label":"Astrid"}]}"#),
+    )
+    .await;
+    assert_eq!(a.status(), StatusCode::CREATED);
+
+    let aid: serde_json::Value =
+        serde_json::from_slice(&a.into_body().collect().await.unwrap().to_bytes()).unwrap();
+    let aid = aid["id"].as_str().unwrap().to_owned();
+
+    // create an authority-typed field definition
+    send(
+        &app,
+        &cookie,
+        "POST",
+        "/api/admin/field-definitions",
+        Some(
+            r#"{"key":"maker","data_type":"authority","vocabulary_id":null,"authority_kind":"person","required":false,"group":null,"labels":[{"lang":"sv","label":"Tillverkare"}]}"#,
+        ),
+    )
+    .await;
+
+    // create an object
+    let obj = send(
+        &app,
+        &cookie,
+        "POST",
+        "/api/admin/objects",
+        Some(
+            r#"{"object_number":"T-1","object_name":"test object","number_of_objects":1,"visibility":"draft"}"#,
+        ),
+    )
+    .await;
+    assert_eq!(obj.status(), StatusCode::CREATED);
+
+    let obj_json: serde_json::Value =
+        serde_json::from_slice(&obj.into_body().collect().await.unwrap().to_bytes()).unwrap();
+    let obj_id = obj_json["id"].as_str().unwrap().to_owned();
+
+    // set the object's maker field to the authority id
+    let fields_body = format!(r#"{{"maker":"{aid}"}}"#);
+    let set = send(
+        &app,
+        &cookie,
+        "PUT",
+        &format!("/api/admin/objects/{obj_id}/fields"),
+        Some(&fields_body),
+    )
+    .await;
+    assert_eq!(set.status(), StatusCode::NO_CONTENT);
+
+    // delete the authority — must be blocked
+    let blocked = send(
+        &app,
+        &cookie,
+        "DELETE",
+        &format!("/api/admin/authorities/{aid}"),
+        None,
+    )
+    .await;
+    assert_eq!(blocked.status(), StatusCode::CONFLICT);
+
+    let body: serde_json::Value =
+        serde_json::from_slice(&blocked.into_body().collect().await.unwrap().to_bytes()).unwrap();
+    assert_eq!(body["count"], 1);
+}
+
+#[sqlx::test(migrations = "../db/migrations")]
+async fn edit_and_delete_authority(pool: PgPool) {
+    migrate_sessions(&db::Db::from_pool(pool.clone()))
+        .await
+        .unwrap();
+
+    seed_user(&pool, "ed@example.com", "pw-editor-123", Role::Editor).await;
+
+    let app = build_app(state(pool));
+    let cookie = login(&app, "ed@example.com", "pw-editor-123").await;
+
+    let a = send(
+        &app,
+        &cookie,
+        "POST",
+        "/api/admin/authorities",
+        Some(r#"{"kind":"person","external_uri":null,"labels":[{"lang":"sv","label":"Anon"}]}"#),
+    )
+    .await;
+    let aid: serde_json::Value =
+        serde_json::from_slice(&a.into_body().collect().await.unwrap().to_bytes()).unwrap();
+    let aid = aid["id"].as_str().unwrap().to_owned();
+
+    let patched = send(
+        &app,
+        &cookie,
+        "PATCH",
+        &format!("/api/admin/authorities/{aid}"),
+        Some(r#"{"external_uri":"https://viaf.org/1","labels":[{"lang":"sv","label":"Astrid"}]}"#),
+    )
+    .await;
+    assert_eq!(patched.status(), StatusCode::NO_CONTENT);
+
+    let deleted = send(
+        &app,
+        &cookie,
+        "DELETE",
+        &format!("/api/admin/authorities/{aid}"),
+        None,
+    )
+    .await;
+    assert_eq!(deleted.status(), StatusCode::NO_CONTENT);
+}
diff --git a/crates/db/src/authority.rs b/crates/db/src/authority.rs
index dc2468f..617f406 100644
--- a/crates/db/src/authority.rs
+++ b/crates/db/src/authority.rs
@@ -124,6 +124,115 @@ where
     }
 }
 
+/// Update an authority's `external_uri` and labels (full replace), recording an
+/// `updated` audit entry. Returns `false` if no such authority. `kind` is immutable.
+pub async fn update_authority(
+    conn: &mut sqlx::PgConnection,
+    actor: AuditActor,
+    id: AuthorityId,
+    external_uri: Option<&str>,
+    labels: &[LocalizedLabel],
+) -> Result<bool, sqlx::Error> {
+    let updated = sqlx::query("UPDATE authority SET external_uri = $2 WHERE id = $1")
+        .bind(id.to_uuid())
+        .bind(external_uri)
+        .execute(&mut *conn)
+        .await?
+        .rows_affected();
+
+    if updated == 0 {
+        return Ok(false);
+    }
+
+    sqlx::query("DELETE FROM authority_label WHERE authority_id = $1")
+        .bind(id.to_uuid())
+        .execute(&mut *conn)
+        .await?;
+
+    for label in labels {
+        sqlx::query("INSERT INTO authority_label (authority_id, lang, label) VALUES ($1, $2, $3)")
+            .bind(id.to_uuid())
+            .bind(&label.lang)
+            .bind(&label.label)
+            .execute(&mut *conn)
+            .await?;
+    }
+
+    audit::record(
+        &mut *conn,
+        &NewAuditEvent {
+            actor,
+            action: AuditAction::Updated,
+            entity_type: AUTHORITY_ENTITY_TYPE.to_owned(),
+            entity_id: id.to_uuid(),
+            changes: Vec::new(),
+        },
+    )
+    .await?;
+
+    Ok(true)
+}
+
+/// Count catalogue objects referencing `id` through an `authority`-typed field.
+pub async fn count_objects_referencing_authority<'e, E>(
+    executor: E,
+    id: AuthorityId,
+) -> Result<i64, sqlx::Error>
+where
+    E: sqlx::PgExecutor<'e>,
+{
+    sqlx::query_scalar(
+        "SELECT count(*) FROM object o WHERE EXISTS ( \
+           SELECT 1 FROM field_definition fd \
+           WHERE fd.data_type = 'authority' AND o.fields ->> fd.key = $1 )",
+    )
+    .bind(id.to_string())
+    .fetch_one(executor)
+    .await
+}
+
+/// Delete an authority (labels cascade) unless catalogue objects reference it,
+/// recording a `deleted` audit entry.
+pub async fn delete_authority(
+    conn: &mut sqlx::PgConnection,
+    actor: AuditActor,
+    id: AuthorityId,
+) -> Result<crate::DeleteOutcome, sqlx::Error> {
+    let exists = sqlx::query_scalar::<_, i32>("SELECT 1 FROM authority WHERE id = $1")
+        .bind(id.to_uuid())
+        .fetch_optional(&mut *conn)
+        .await?;
+
+    if exists.is_none() {
+        return Ok(crate::DeleteOutcome::NotFound);
+    }
+
+    let count = count_objects_referencing_authority(&mut *conn, id).await?;
+
+    if count > 0 {
+        return Ok(crate::DeleteOutcome::InUse { count });
+    }
+
+    sqlx::query("DELETE FROM authority WHERE id = $1")
+        .bind(id.to_uuid())
+        .execute(&mut *conn)
+        .await?;
+
+    audit::record(
+        &mut *conn,
+        &NewAuditEvent {
+            actor,
+            action: AuditAction::Deleted,
+            entity_type: AUTHORITY_ENTITY_TYPE.to_owned(),
+            entity_id: id.to_uuid(),
+            changes: Vec::new(),
+        },
+    )
+    .await?;
+
+    Ok(crate::DeleteOutcome::Deleted)
+}
+
 fn map_authority(row: sqlx::postgres::PgRow) -> Result<Authority, sqlx::Error> {
     let kind_str: String = row.try_get("kind")?;
     let kind = AuthorityKind::from_db(&kind_str)
diff --git a/crates/db/tests/authority.rs b/crates/db/tests/authority.rs
index c7ebc51..36bff06 100644
--- a/crates/db/tests/authority.rs
+++ b/crates/db/tests/authority.rs
@@ -1,7 +1,23 @@
-use db::{Db, authority};
-use domain::{AuditActor, AuthorityKind, LocalizedLabel, NewAuthority};
+use db::{Db, authority, catalog, fields};
+use domain::{
+    AuditActor, AuthorityKind, LocalizedLabel, NewAuthority, NewFieldDefinition, Visibility,
+};
 use sqlx::PgPool;
 
+fn sample_object_input() -> domain::ObjectInput {
+    domain::ObjectInput {
+        object_number: "X.1".into(),
+        object_name: "Test".into(),
+        number_of_objects: 1,
+        brief_description: None,
+        current_location: None,
+        current_owner: None,
+        recorder: None,
+        recording_date: None,
+        visibility: Visibility::Draft,
+    }
+}
+
 fn new_person(name_sv: &str, name_en: &str) -> NewAuthority {
     NewAuthority {
         kind: AuthorityKind::Person,
@@ -131,3 +147,117 @@ async fn authority_with_no_labels_round_trips_empty(pool: PgPool) {
     assert_eq!(got.kind, AuthorityKind::Organisation);
     assert!(got.labels.is_empty());
 }
+
+#[sqlx::test(migrations = "../db/migrations")]
+async fn update_authority_changes_labels(pool: PgPool) {
+    let db = Db::from_pool(pool);
+    let mut tx = db.pool().begin().await.unwrap();
+    let id = authority::create_authority(
+        &mut tx,
+        AuditActor::System,
+        &NewAuthority {
+            kind: AuthorityKind::Person,
+            external_uri: None,
+            labels: vec![LocalizedLabel {
+                lang: "sv".into(),
+                label: "Anon".into(),
+            }],
+        },
+    )
+    .await
+    .unwrap();
+
+    let existed = authority::update_authority(
+        &mut tx,
+        AuditActor::System,
+        id,
+        Some("https://viaf.org/1"),
+        &[LocalizedLabel {
+            lang: "sv".into(),
+            label: "Astrid".into(),
+        }],
+    )
+    .await
+    .unwrap();
+    assert!(existed);
+    tx.commit().await.unwrap();
+
+    let a = authority::authority_by_id(db.pool(), id)
+        .await
+        .unwrap()
+        .unwrap();
+    assert_eq!(a.external_uri.as_deref(), Some("https://viaf.org/1"));
+    assert_eq!(a.labels[0].label, "Astrid");
+}
+
+#[sqlx::test(migrations = "../db/migrations")]
+async fn delete_authority_blocks_when_referenced(pool: PgPool) {
+    use db::DeleteOutcome;
+
+    let db = Db::from_pool(pool);
+    let mut tx = db.pool().begin().await.unwrap();
+    let id = authority::create_authority(
+        &mut tx,
+        AuditActor::System,
+        &NewAuthority {
+            kind: AuthorityKind::Person,
+            external_uri: None,
+            labels: vec![LocalizedLabel {
+                lang: "sv".into(),
+                label: "Astrid".into(),
+            }],
+        },
+    )
+    .await
+    .unwrap();
+
+    fields::create_field_definition(
+        &mut tx,
+        &NewFieldDefinition {
+            key: "maker".into(),
+            field_type: domain::FieldType::Authority {
+                kind: Some(AuthorityKind::Person),
+            },
+            required: false,
+            group_key: None,
+            labels: vec![LocalizedLabel {
+                lang: "sv".into(),
+                label: "Tillverkare".into(),
+            }],
+        },
+    )
+    .await
+    .unwrap();
+
+    let obj = catalog::create_object(&mut tx, AuditActor::System, &sample_object_input())
+        .await
+        .unwrap();
+    let mut map = serde_json::Map::new();
+    map.insert("maker".into(), serde_json::Value::String(id.to_string()));
+    catalog::set_object_fields(&mut tx, AuditActor::System, obj, &map)
+        .await
+        .unwrap();
+
+    assert_eq!(
+        authority::delete_authority(&mut tx, AuditActor::System, id)
+            .await
+            .unwrap(),
+        DeleteOutcome::InUse { count: 1 }
+    );
+
+    catalog::set_object_fields(&mut tx, AuditActor::System, obj, &serde_json::Map::new())
+        .await
+        .unwrap();
+    assert_eq!(
+        authority::delete_authority(&mut tx, AuditActor::System, id)
+            .await
+            .unwrap(),
+        DeleteOutcome::Deleted
+    );
+    assert_eq!(
+        authority::delete_authority(&mut tx, AuditActor::System, id)
+            .await
+            .unwrap(),
+        DeleteOutcome::NotFound
+    );
+}