diff --git a/server/src/adresar/tests/mod.rs b/server/src/adresar/tests/mod.rs
index f8829c3..a6e60d6 100644
--- a/server/src/adresar/tests/mod.rs
+++ b/server/src/adresar/tests/mod.rs
@@ -1,3 +1,4 @@
 // src/adresar/tests/mod.rs
 
 pub mod post_adresar_test;
+pub mod put_adresar_test;
diff --git a/server/src/adresar/tests/put_adresar_test.rs b/server/src/adresar/tests/put_adresar_test.rs
new file mode 100644
index 0000000..e86dd2e
--- /dev/null
+++ b/server/src/adresar/tests/put_adresar_test.rs
@@ -0,0 +1,210 @@
+// src/adresar/tests/put_adresar_test.rs
+use super::super::handlers::put_adresar;
+use common::proto::multieko2::adresar::{AdresarResponse, PutAdresarRequest};
+use sqlx::{postgres::PgPoolOptions, PgPool};
+use std::env;
+
+mod test_helpers {
+    use super::*;
+
+    pub async fn setup_test_db() -> (PgPool, i64) {
+        dotenvy::from_filename(".env_test").ok();
+        let pool = PgPoolOptions::new()
+            .max_connections(5)
+            .connect(&env::var("TEST_DATABASE_URL").unwrap())
+            .await
+            .unwrap();
+
+        sqlx::migrate!()
+            .run(&pool)
+            .await
+            .expect("Migrations failed");
+
+        let record = sqlx::query!(
+            r#"
+            INSERT INTO adresar (
+                firma, kz, drc, ulica, psc, mesto, stat, banka, ucet,
+                skladm, ico, kontakt, telefon, skladu, fax, deleted
+            )
+            VALUES (
+                'Original Company', 'Original KZ', 'Original DRC', 'Original Street',
+                '12345', 'Original City', 'Original Country', 'Original Bank',
+                'Original Account', 'Original SkladM', 'Original ICO',
+                'Original Contact', '+421123456789', 'Original SkladU', 'Original Fax',
+                false
+            )
+            RETURNING id
+            "#
+        )
+        .fetch_one(&pool)
+        .await
+        .unwrap();
+
+        (pool, record.id)
+    }
+
+    pub fn valid_put_request(id: i64) -> PutAdresarRequest {
+        PutAdresarRequest {
+            id,
+            firma: "Updated Company".into(),
+            kz: "Updated KZ".into(),
+            drc: "Updated DRC".into(),
+            ulica: "Updated Street".into(),
+            psc: "67890".into(),
+            mesto: "Updated City".into(),
+            stat: "Updated Country".into(),
+            banka: "Updated Bank".into(),
+            ucet: "987654321".into(),
+            skladm: "Updated SkladM".into(),
+            ico: "87654321".into(),
+            kontakt: "Jane Doe".into(),
+            telefon: "+421987654321".into(),
+            skladu: "Updated SkladU".into(),
+            fax: "+421987654300".into(),
+        }
+    }
+
+
+    pub async fn assert_response_matches(pool: &PgPool, id: i64, response: &AdresarResponse) {
+        let db_record = sqlx::query!("SELECT * FROM adresar WHERE id = $1", id)
+            .fetch_one(pool)
+            .await
+            .unwrap();
+
+        assert_eq!(db_record.firma, response.firma);
+        assert_eq!(db_record.kz.unwrap_or_default(), response.kz);
+        assert_eq!(db_record.drc.unwrap_or_default(), response.drc);
+        assert_eq!(db_record.ulica.unwrap_or_default(), response.ulica);
+        assert_eq!(db_record.psc.unwrap_or_default(), response.psc);
+        assert_eq!(db_record.mesto.unwrap_or_default(), response.mesto);
+        assert_eq!(db_record.stat.unwrap_or_default(), response.stat);
+        assert_eq!(db_record.banka.unwrap_or_default(), response.banka);
+        assert_eq!(db_record.ucet.unwrap_or_default(), response.ucet);
+        assert_eq!(db_record.skladm.unwrap_or_default(), response.skladm);
+        assert_eq!(db_record.ico.unwrap_or_default(), response.ico);
+        assert_eq!(db_record.kontakt.unwrap_or_default(), response.kontakt);
+        assert_eq!(db_record.telefon.unwrap_or_default(), response.telefon);
+        assert_eq!(db_record.skladu.unwrap_or_default(), response.skladu);
+        assert_eq!(db_record.fax.unwrap_or_default(), response.fax);
+        assert!(!db_record.deleted, "Record should not be deleted");
+    }
+}
+
+#[tokio::test]
+async fn test_update_adresar_success() {
+    let (pool, existing_id) = test_helpers::setup_test_db().await;
+    let request = test_helpers::valid_put_request(existing_id);
+
+    let response = put_adresar(&pool, request).await.unwrap();
+
+    assert_eq!(response.id, existing_id);
+    test_helpers::assert_response_matches(&pool, existing_id, &response).await;
+}
+
+#[tokio::test]
+async fn test_update_whitespace_fields() {
+    let (pool, existing_id) = test_helpers::setup_test_db().await;
+    let mut request = test_helpers::valid_put_request(existing_id);
+    request.firma = "  Updated Company  ".into();
+    request.telefon = "  +421987654321  ".into();
+
+    let _response = put_adresar(&pool, request).await.unwrap();
+
+    let db_record = sqlx::query!("SELECT firma, telefon FROM adresar WHERE id = $1", existing_id)
+        .fetch_one(&pool)
+        .await
+        .unwrap();
+
+    assert_eq!(db_record.firma, "  Updated Company  ");
+    assert_eq!(db_record.telefon.unwrap(), "  +421987654321  ");
+}
+
+#[tokio::test]
+async fn test_update_empty_required_field() {
+    let (pool, existing_id) = test_helpers::setup_test_db().await;
+    let mut request = test_helpers::valid_put_request(existing_id);
+    request.firma = "".into();
+
+    let result = put_adresar(&pool, request).await;
+    assert!(result.is_err());
+    assert_eq!(result.unwrap_err().code(), tonic::Code::Internal);
+}
+
+#[tokio::test]
+async fn test_update_nonexistent_id() {
+    let (pool, _) = test_helpers::setup_test_db().await;
+    let request = test_helpers::valid_put_request(9999);
+
+    let result = put_adresar(&pool, request).await;
+    assert!(result.is_err());
+    assert_eq!(result.unwrap_err().code(), tonic::Code::Internal);
+}
+
+#[tokio::test]
+async fn test_update_deleted_record() {
+    let (pool, existing_id) = test_helpers::setup_test_db().await;
+    sqlx::query!("UPDATE adresar SET deleted = true WHERE id = $1", existing_id)
+        .execute(&pool)
+        .await
+        .unwrap();
+
+    let request = test_helpers::valid_put_request(existing_id);
+    let result = put_adresar(&pool, request).await;
+
+    assert!(result.is_err());
+    assert_eq!(result.unwrap_err().code(), tonic::Code::Internal);
+}
+
+#[tokio::test]
+async fn test_clear_optional_fields() {
+    let (pool, existing_id) = test_helpers::setup_test_db().await;
+    let mut request = test_helpers::valid_put_request(existing_id);
+    request.telefon = String::new();
+    request.ulica = String::new();
+
+    let _response = put_adresar(&pool, request).await.unwrap();
+
+    let db_record = sqlx::query!("SELECT telefon, ulica FROM adresar WHERE id = $1", existing_id)
+        .fetch_one(&pool)
+        .await
+        .unwrap();
+
+    assert_eq!(db_record.telefon.unwrap(), "");
+    assert_eq!(db_record.ulica.unwrap(), "");
+}
+
+#[tokio::test]
+async fn test_max_length_fields() {
+    let (pool, existing_id) = test_helpers::setup_test_db().await;
+    let mut request = test_helpers::valid_put_request(existing_id);
+    request.firma = "a".repeat(255);
+    request.telefon = "1".repeat(20);
+
+    let _response = put_adresar(&pool, request).await.unwrap();
+
+    let db_record = sqlx::query!("SELECT firma, telefon FROM adresar WHERE id = $1", existing_id)
+        .fetch_one(&pool)
+        .await
+        .unwrap();
+
+    assert_eq!(db_record.firma.len(), 255);
+    assert_eq!(db_record.telefon.unwrap().len(), 20);
+}
+
+#[tokio::test]
+async fn test_special_characters() {
+    let (pool, existing_id) = test_helpers::setup_test_db().await;
+    let mut request = test_helpers::valid_put_request(existing_id);
+    request.ulica = "Náměstí 28. října".into();
+    request.telefon = "+420 123-456.789".into();
+
+    let _response = put_adresar(&pool, request).await.unwrap();
+
+    let db_record = sqlx::query!("SELECT ulica, telefon FROM adresar WHERE id = $1", existing_id)
+        .fetch_one(&pool)
+        .await
+        .unwrap();
+
+    assert_eq!(db_record.ulica.unwrap(), "Náměstí 28. října");
+    assert_eq!(db_record.telefon.unwrap(), "+420 123-456.789");
+}