diff --git a/server/Cargo.toml b/server/Cargo.toml
index e6f4f97..efce36a 100644
--- a/server/Cargo.toml
+++ b/server/Cargo.toml
@@ -26,3 +26,4 @@ path = "src/lib.rs"
 tokio = { version = "1.0", features = ["full", "test-util"] }
 dotenv = "0.15"
 rstest = "0.24.0"
+lazy_static = "1.5.0"
diff --git a/server/tests/adresar/get_adresar_count_test.rs b/server/tests/adresar/get_adresar_count_test.rs
index 2e1e5d3..7b6047c 100644
--- a/server/tests/adresar/get_adresar_count_test.rs
+++ b/server/tests/adresar/get_adresar_count_test.rs
@@ -5,20 +5,19 @@ use common::proto::multieko2::common::Empty;
 use crate::common::setup_test_db;
 use sqlx::PgPool;
 use tonic;
+use std::sync::Arc;
+use tokio::sync::Mutex;
+
+// Use a global mutex to synchronize test execution
+// This prevents tests from interfering with each other
+lazy_static::lazy_static! {
+    static ref TEST_MUTEX: Arc<Mutex<()>> = Arc::new(Mutex::new(()));
+}
 
 #[fixture]
 async fn pool() -> PgPool {
-    let pool = setup_test_db().await;
-
-    // Ensure sequence is set correctly to avoid primary key conflicts
-    sqlx::query_scalar!(
-        "SELECT setval('adresar_id_seq', COALESCE((SELECT MAX(id) FROM adresar), 0) + 1, false)"
-    )
-    .fetch_one(&pool)
-    .await
-    .unwrap();
-
-    pool
+    // Just connect to the test database without truncating anything
+    setup_test_db().await
 }
 
 #[fixture]
@@ -32,26 +31,16 @@ async fn closed_pool(#[future] pool: PgPool) -> PgPool {
 #[tokio::test]
 async fn test_count_increments_after_adding_record(#[future] pool: PgPool) {
     let pool = pool.await;
+    
+    // Lock to prevent concurrent test execution
+    let _guard = TEST_MUTEX.lock().await;
 
     // Get initial count of active records
-    let initial_count = sqlx::query_scalar!("SELECT COUNT(*) FROM adresar WHERE deleted = FALSE")
-        .fetch_one(&pool)
-        .await
-        .unwrap()
-        .unwrap_or(0);
-
-    // Verify initial count from handler
     let initial_response = get_adresar_count(&pool, Empty {}).await.unwrap();
-    assert_eq!(initial_response.count, initial_count);
-
-    // Generate unique identifier for test data
-    let test_id = std::time::SystemTime::now()
-        .duration_since(std::time::UNIX_EPOCH)
-        .unwrap()
-        .as_millis();
+    let initial_count = initial_response.count;
 
     // Insert new active record with unique name
-    let unique_name = format!("Test Company {}", test_id);
+    let unique_name = format!("Test Company {}", chrono::Utc::now().timestamp_millis());
     sqlx::query!(
         "INSERT INTO adresar (firma, deleted) VALUES ($1, FALSE)",
         unique_name
@@ -67,68 +56,121 @@ async fn test_count_increments_after_adding_record(#[future] pool: PgPool) {
 
 #[rstest]
 #[tokio::test]
-async fn test_deleted_records_not_counted(#[future] pool: PgPool) {
+async fn test_add_multiple_records_and_check_count(#[future] pool: PgPool) {
     let pool = pool.await;
+    
+    // Lock to prevent concurrent test execution
+    let _guard = TEST_MUTEX.lock().await;
 
     // Get initial count
-    let initial_count = sqlx::query_scalar!("SELECT COUNT(*) FROM adresar WHERE deleted = FALSE")
-        .fetch_one(&pool)
+    let initial_response = get_adresar_count(&pool, Empty {}).await.unwrap();
+    let initial_count = initial_response.count;
+
+    // Add 5 active records
+    let timestamp = chrono::Utc::now().timestamp_millis();
+    for i in 0..5 {
+        let unique_name = format!("Batch Company {} #{}", timestamp, i);
+        sqlx::query!(
+            "INSERT INTO adresar (firma, deleted) VALUES ($1, FALSE)",
+            unique_name
+        )
+        .execute(&pool)
         .await
-        .unwrap()
-        .unwrap_or(0);
+        .unwrap();
+    }
 
-    // Generate unique test identifier
-    let test_id = std::time::SystemTime::now()
-        .duration_since(std::time::UNIX_EPOCH)
-        .unwrap()
-        .as_millis();
+    // Verify count increased by 5
+    let updated_response = get_adresar_count(&pool, Empty {}).await.unwrap();
+    assert_eq!(updated_response.count, initial_count + 5);
+}
 
-    // Insert test records (2 active, 1 deleted)
-    let max_id = sqlx::query_scalar!("SELECT COALESCE(MAX(id), 0) FROM adresar")
-        .fetch_one(&pool)
+#[rstest]
+#[tokio::test]
+async fn test_deleted_records_not_counted(#[future] pool: PgPool) {
+    let pool = pool.await;
+    
+    // Lock to prevent concurrent test execution
+    let _guard = TEST_MUTEX.lock().await;
+
+    // Get initial count
+    let initial_response = get_adresar_count(&pool, Empty {}).await.unwrap();
+    let initial_count = initial_response.count;
+
+    // Generate unique identifier for test
+    let timestamp = chrono::Utc::now().timestamp_millis();
+
+    // Insert 5 test records (2 active, 3 deleted)
+    for i in 0..5 {
+        let is_deleted = i >= 2; // First 2 active, next 3 deleted
+        let unique_name = format!("Deletion Test {} #{}", timestamp, i);
+
+        sqlx::query!(
+            "INSERT INTO adresar (firma, deleted) VALUES ($1, $2)",
+            unique_name,
+            is_deleted
+        )
+        .execute(&pool)
         .await
-        .unwrap()
-        .unwrap_or(0);
+        .unwrap();
+    }
 
-    sqlx::query!(
-        "INSERT INTO adresar (id, firma, deleted) VALUES ($1, $2, FALSE)",
-        max_id + 1,
-        format!("Active 1 {}", test_id)
-    )
-    .execute(&pool)
-    .await
-    .unwrap();
+    // Verify count only increased by 2 (the non-deleted records)
+    let updated_response = get_adresar_count(&pool, Empty {}).await.unwrap();
+    assert_eq!(updated_response.count, initial_count + 2);
+}
 
-    sqlx::query!(
-        "INSERT INTO adresar (id, firma, deleted) VALUES ($1, $2, TRUE)",
-        max_id + 2,
-        format!("Deleted {}", test_id)
-    )
-    .execute(&pool)
-    .await
-    .unwrap();
+#[rstest]
+#[tokio::test]
+async fn test_mark_existing_record_as_deleted(#[future] pool: PgPool) {
+    let pool = pool.await;
+    
+    // Lock to prevent concurrent test execution
+    let _guard = TEST_MUTEX.lock().await;
 
-    sqlx::query!(
-        "INSERT INTO adresar (id, firma, deleted) VALUES ($1, $2, FALSE)",
-        max_id + 3,
-        format!("Active 2 {}", test_id)
-    )
-    .execute(&pool)
-    .await
-    .unwrap();
+    // Get initial count
+    let initial_response = get_adresar_count(&pool, Empty {}).await.unwrap();
+    let initial_count = initial_response.count;
 
-    // Verify count only includes active records
-    let response = get_adresar_count(&pool, Empty {}).await.unwrap();
-    assert_eq!(response.count, initial_count + 2);
-
-    // Reset sequence to maintain test stability
-    sqlx::query_scalar!(
-        "SELECT setval('adresar_id_seq', $1, true)",
-        max_id + 4
+    // Insert one record
+    let unique_name = format!("Delete Me {}", chrono::Utc::now().timestamp_millis());
+    let record_id = sqlx::query_scalar!(
+        "INSERT INTO adresar (firma, deleted) VALUES ($1, FALSE) RETURNING id",
+        unique_name
     )
     .fetch_one(&pool)
     .await
     .unwrap();
+
+    // Verify count increased by 1
+    let after_insert_response = get_adresar_count(&pool, Empty {}).await.unwrap();
+    assert_eq!(after_insert_response.count, initial_count + 1);
+
+    // Mark record as deleted
+    sqlx::query!(
+        "UPDATE adresar SET deleted = TRUE WHERE id = $1",
+        record_id
+    )
+    .execute(&pool)
+    .await
+    .unwrap();
+
+    // Verify count decreased back to initial
+    let after_delete_response = get_adresar_count(&pool, Empty {}).await.unwrap();
+    assert_eq!(after_delete_response.count, initial_count);
+}
+
+#[rstest]
+#[tokio::test]
+async fn test_edge_case_empty_table(#[future] pool: PgPool) {
+    let pool = pool.await;
+
+    // Get current count (whatever it is)
+    let current_response = get_adresar_count(&pool, Empty {}).await.unwrap();
+    let current_count = current_response.count;
+
+    // We're not going to empty the table (could violate FK constraints)
+    // But we can at least verify that the count is non-negative
+    assert!(current_count >= 0);
 }
 
 #[rstest]
@@ -139,3 +181,56 @@ async fn test_database_error(#[future] closed_pool: PgPool) {
     assert!(result.is_err());
     assert_eq!(result.unwrap_err().code(), tonic::Code::Internal);
 }
+
+#[rstest]
+#[tokio::test]
+async fn test_toggle_deleted_status(#[future] pool: PgPool) {
+    let pool = pool.await;
+    
+    // Lock to prevent concurrent test execution
+    let _guard = TEST_MUTEX.lock().await;
+
+    // Get initial count
+    let initial_response = get_adresar_count(&pool, Empty {}).await.unwrap();
+    let initial_count = initial_response.count;
+
+    // Create a new record that will be toggled
+    let unique_name = format!("Toggle Me {}", chrono::Utc::now().timestamp_millis());
+    let record_id = sqlx::query_scalar!(
+        "INSERT INTO adresar (firma, deleted) VALUES ($1, FALSE) RETURNING id",
+        unique_name
+    )
+    .fetch_one(&pool)
+    .await
+    .unwrap();
+
+    // Verify count increased by 1
+    let after_insert_response = get_adresar_count(&pool, Empty {}).await.unwrap();
+    assert_eq!(after_insert_response.count, initial_count + 1);
+
+    // Mark as deleted
+    sqlx::query!(
+        "UPDATE adresar SET deleted = TRUE WHERE id = $1",
+        record_id
+    )
+    .execute(&pool)
+    .await
+    .unwrap();
+
+    // Verify count back to initial
+    let after_delete_response = get_adresar_count(&pool, Empty {}).await.unwrap();
+    assert_eq!(after_delete_response.count, initial_count);
+
+    // Mark as NOT deleted
+    sqlx::query!(
+        "UPDATE adresar SET deleted = FALSE WHERE id = $1",
+        record_id
+    )
+    .execute(&pool)
+    .await
+    .unwrap();
+
+    // Verify count increased again
+    let after_undelete_response = get_adresar_count(&pool, Empty {}).await.unwrap();
+    assert_eq!(after_undelete_response.count, initial_count + 1);
+}