diff --git a/storage/postgresql.go b/storage/postgresql.go
index 5804e13..69caf9e 100644
--- a/storage/postgresql.go
+++ b/storage/postgresql.go
@@ -47,24 +47,24 @@ func (psql PostgresqlStorage) GetAccount(id string) (*Account, error) {
 	if isUUIDv4(id) {
 		stmtAccounts, err := psql.DbConnection.Prepare("SELECT id, namespace, data, metadata FROM accounts WHERE id = $1")
 		if err != nil {
-			return account, fmt.Errorf("psql connection failed")
+			return nil, fmt.Errorf("psql connection failed")
 		}
 		defer stmtAccounts.Close()
 		err = stmtAccounts.QueryRow(id).Scan(&account.ID, &account.Namespace, &data, &metadata)
 		if err != nil {
-			return account, fmt.Errorf("psql select account query failed")
+			return nil, fmt.Errorf("psql select account query failed")
 		}
 		err = json.Unmarshal(data, &account.Data)
 		if err != nil {
-			return account, err
+			return nil, err
 		}
 		err = json.Unmarshal(metadata, &account.Metadata)
 		if err != nil {
-			return account, err
+			return nil, err
 		}
 		stmtAccount_auth, err := psql.DbConnection.Prepare("SELECT username, password, email, email_validation, phone_number, phone_number_validation FROM account_auth WHERE account_id= $1")
 		if err != nil {
-			return account, fmt.Errorf("psql connection failed")
+			return nil, fmt.Errorf("psql connection failed")
 		}
 		defer stmtAccount_auth.Close()
 		err = stmtAccount_auth.QueryRow(id).Scan(&account.Authentication.Local.Username,
@@ -74,22 +74,110 @@ func (psql PostgresqlStorage) GetAccount(id string) (*Account, error) {
 			&account.Authentication.Local.PhoneNumber,
 			&phoneValidation)
 		if err != nil {
-			return account, fmt.Errorf("psql select account auth query failed")
+			return nil, fmt.Errorf("psql select account auth query failed")
 		}
 		err = json.Unmarshal(emailValidation, &account.Authentication.Local.EmailValidation)
 		if err != nil {
-			return account, err
+			return nil, err
 		}
 		err = json.Unmarshal(phoneValidation, &account.Authentication.Local.PhoneNumberValidation)
 		if err != nil {
-			return account, err
+			return nil, err
 		}
 	}
 	return account, nil
 }
 
-func (PostgresqlStorage) LocalAuthentication(namespace string, username string, email string, phone_number string) (*Account, error) {
-	return nil, fmt.Errorf("")
+func (psql PostgresqlStorage) LocalAuthentication(namespace string, username string, email string, phone_number string) (*Account, error) {
+	account := &Account{}
+	var (
+		data, metadata, emailValidation, phoneValidation []byte
+	)
+	if username != "" {
+		usernameStmt, err := psql.DbConnection.Prepare("SELECT id, namespace, data, metadata, username, password, email, email_validation, phone_number, phone_number_validation FROM accounts INNER JOIN account_auth ON accounts.id = account_auth.account_id WHERE namespace = $1 AND username = $2;")
+		if err != nil {
+			return nil, err
+		}
+		err = usernameStmt.QueryRow(namespace, username).Scan(&account.ID, &account.Namespace, &data, &metadata, &account.Authentication.Local.Username,
+			&account.Authentication.Local.Password, &account.Authentication.Local.Email, &emailValidation, &account.Authentication.Local.PhoneNumber, &phoneValidation)
+		if err != nil {
+			return nil, err
+		}
+		err = json.Unmarshal(metadata, &account.Metadata)
+		if err != nil {
+			return nil, err
+		}
+		err = json.Unmarshal(data, &account.Data)
+		if err != nil {
+			return nil, err
+		}
+		err = json.Unmarshal(emailValidation, &account.Authentication.Local.EmailValidation)
+		if err != nil {
+			return nil, err
+		}
+		err = json.Unmarshal(phoneValidation, &account.Authentication.Local.PhoneNumberValidation)
+		if err != nil {
+			return nil, err
+		}
+		return account, nil
+	} else if email != "" {
+		account.Authentication.Local.Email = email
+		emailStmt, err := psql.DbConnection.Prepare("SELECT id, namespace, data, metadata, username, password, email_validation, phone_number, phone_number_validation FROM accounts INNER JOIN account_auth ON accounts.id = account_auth.account_id WHERE namespace = $1 AND email = $2;")
+		if err != nil {
+			return nil, err
+		}
+		err = emailStmt.QueryRow(namespace, email).Scan(&account.ID, &account.Namespace, &data, &metadata, &account.Authentication.Local.Username,
+			&account.Authentication.Local.Password, &emailValidation, &account.Authentication.Local.PhoneNumber, &phoneValidation)
+		if err != nil {
+			return nil, err
+		}
+		err = json.Unmarshal(metadata, &account.Metadata)
+		if err != nil {
+			return nil, err
+		}
+		err = json.Unmarshal(data, &account.Data)
+		if err != nil {
+			return nil, err
+		}
+		err = json.Unmarshal(emailValidation, &account.Authentication.Local.EmailValidation)
+		if err != nil {
+			return nil, err
+		}
+		err = json.Unmarshal(phoneValidation, &account.Authentication.Local.PhoneNumberValidation)
+		if err != nil {
+			return nil, err
+		}
+		return account, nil
+	} else if phone_number != "" {
+		account.Authentication.Local.PhoneNumber = phone_number
+		phoneStmt, err := psql.DbConnection.Prepare("SELECT id, namespace, data, metadata, username, password, email, email_validation, phone_number_validation FROM accounts INNER JOIN account_auth ON accounts.id = account_auth.account_id WHERE namespace = $1 AND phone_number = $2;")
+		if err != nil {
+			return nil, err
+		}
+		err = phoneStmt.QueryRow(namespace, phone_number).Scan(&account.ID, &account.Namespace, &data, &metadata, &account.Authentication.Local.Username,
+			&account.Authentication.Local.Password, &account.Authentication.Local.Email, &emailValidation, &phoneValidation)
+		if err != nil {
+			return nil, err
+		}
+		err = json.Unmarshal(metadata, &account.Metadata)
+		if err != nil {
+			return nil, err
+		}
+		err = json.Unmarshal(data, &account.Data)
+		if err != nil {
+			return nil, err
+		}
+		err = json.Unmarshal(emailValidation, &account.Authentication.Local.EmailValidation)
+		if err != nil {
+			return nil, err
+		}
+		err = json.Unmarshal(phoneValidation, &account.Authentication.Local.PhoneNumberValidation)
+		if err != nil {
+			return nil, err
+		}
+		return account, nil
+	}
+	return account, nil
 }
 
 func (PostgresqlStorage) GetAccounts(namespaces []string) ([]Account, error) {
diff --git a/storage/postgresql_test.go b/storage/postgresql_test.go
index cf35713..08383e5 100644
--- a/storage/postgresql_test.go
+++ b/storage/postgresql_test.go
@@ -23,6 +23,8 @@ func init() {
 
 func TestNewPostgresqlStorage(t *testing.T) {
 	storage, err := NewPostgresqlStorage(cfg)
+	storage.DbConnection.Exec("Delete from accounts;")
+	storage.DbConnection.Exec("Delete from account_auth;")
 	if err != nil {
 		t.Errorf("error creating new PostgreSQL storage: %v", err)
 	}
@@ -144,7 +146,7 @@ func TestPostgresqlStorage_CreateAccount(t *testing.T) {
 	}
 	account := Account{
 		ID:        Id,
-		Namespace: "test_namespace",
+		Namespace: "namespace",
 		Authentication: AccountAuth{
 			Local: localAuth,
 		},
@@ -232,3 +234,30 @@ func TestPostgresqlStorage_UpdateAccount(t *testing.T) {
 		t.Errorf("failed")
 	}
 }
+
+func TestPostgresqlStorage_LocalAuthentication(t *testing.T) {
+	db, err := NewPostgresqlStorage(cfg)
+	if err != nil {
+		t.Errorf("failed to create new psql connection")
+	}
+	accountByUsername, err := db.LocalAuthentication("test_namespace", "testuser", "", "")
+	if err != nil {
+		t.Errorf("Failed LocalAuthentication based on username and namespace")
+	}
+	fmt.Println(accountByUsername)
+	accountByEmail, err := db.LocalAuthentication("test_namespace", "", "test@test.com", "")
+	if err != nil {
+		t.Errorf("Failed LocalAuthentication based on username and namespace")
+	}
+	fmt.Println(accountByEmail)
+	accountByPhone, err := db.LocalAuthentication("test_namespace", "", "", "1234567890")
+	if err != nil {
+		t.Errorf("Failed LocalAuthentication based on username and namespace")
+	}
+	fmt.Println(accountByPhone)
+	accountByAll, err := db.LocalAuthentication("test_namespace", "testuser", "test@test.com", "1234567890")
+	if err != nil {
+		t.Errorf("Failed LocalAuthentication based on username and namespace")
+	}
+	fmt.Println(accountByAll)
+}