diff --git a/src/identity/adapters/output/db/postgres/create_verification_secret.rs b/src/identity/adapters/output/db/postgres/create_verification_secret.rs
index c825589..08287be 100644
--- a/src/identity/adapters/output/db/postgres/create_verification_secret.rs
+++ b/src/identity/adapters/output/db/postgres/create_verification_secret.rs
@@ -48,7 +48,7 @@ mod tests {
         // duplicate: secret exists
         assert_eq!(
             db.create_verification_secret(msg).await.err(),
-            Some(OutDBPortError::VerificationOTPSecretExists)
+            Some(OutDBPortError::DuplicateVerificationOTPSecret)
         );
 
         settings.drop_db().await;
diff --git a/src/identity/adapters/output/db/postgres/errors.rs b/src/identity/adapters/output/db/postgres/errors.rs
index d9772e9..449a278 100644
--- a/src/identity/adapters/output/db/postgres/errors.rs
+++ b/src/identity/adapters/output/db/postgres/errors.rs
@@ -19,7 +19,7 @@ impl From<SqlxError> for OutDBPortError {
                 } else if msg.contains("user_query_email_key") {
                     return Self::InternalError;
                 } else if msg.contains("verification_otp_secret_key") {
-                    return Self::VerificationOTPSecretExists;
+                    return Self::DuplicateVerificationOTPSecret;
                 } else {
                     println!("{msg}");
                 }
@@ -28,3 +28,12 @@ impl From<SqlxError> for OutDBPortError {
         Self::InternalError
     }
 }
+
+/// map custom row not found error to DB error
+pub fn map_row_not_found_err(e: SqlxError, row_not_found: OutDBPortError) -> OutDBPortError {
+    if let SqlxError::RowNotFound = e {
+        row_not_found
+    } else {
+        e.into()
+    }
+}
diff --git a/src/identity/application/port/output/db/errors.rs b/src/identity/application/port/output/db/errors.rs
index 09a9874..fb34cd8 100644
--- a/src/identity/application/port/output/db/errors.rs
+++ b/src/identity/application/port/output/db/errors.rs
@@ -10,5 +10,6 @@ pub type OutDBPortResult<V> = Result<V, OutDBPortError>;
 #[derive(Debug, Display, Clone, Serialize, Deserialize, PartialEq, Eq, PartialOrd, Ord)]
 pub enum OutDBPortError {
     InternalError,
-    VerificationOTPSecretExists,
+    DuplicateVerificationOTPSecret,
+    VerificationOTPSecretNotFound,
 }
diff --git a/src/identity/application/port/output/db/mod.rs b/src/identity/application/port/output/db/mod.rs
index 67f9db9..e4a00f7 100644
--- a/src/identity/application/port/output/db/mod.rs
+++ b/src/identity/application/port/output/db/mod.rs
@@ -6,5 +6,6 @@ pub mod create_verification_secret;
 pub mod delete_verification_secret;
 pub mod email_exists;
 pub mod errors;
+pub mod get_verification_secret;
 pub mod username_exists;
 pub mod verification_secret_exists;
diff --git a/src/identity/application/services/errors.rs b/src/identity/application/services/errors.rs
index 50bdbb3..5454b1c 100644
--- a/src/identity/application/services/errors.rs
+++ b/src/identity/application/services/errors.rs
@@ -10,9 +10,9 @@ pub type IdentityResult<V> = Result<V, IdentityError>;
 
 #[derive(Debug, Display, Clone, Serialize, Deserialize, PartialEq, Eq, PartialOrd, Ord)]
 pub enum IdentityError {
-    UsernameExists,
-    VerificationOTPSecretDoesntExist,
-    EmailExists,
+    DuplicateUsername,
+    VerificationOTPSecretNotFound,
+    DuplicateEmail,
 }
 
 pub type IdentityCommandResult<V> = Result<V, IdentityCommandError>;
diff --git a/src/identity/application/services/mark_user_verified/service.rs b/src/identity/application/services/mark_user_verified/service.rs
index b744ab1..fc9bcec 100644
--- a/src/identity/application/services/mark_user_verified/service.rs
+++ b/src/identity/application/services/mark_user_verified/service.rs
@@ -31,7 +31,7 @@ impl MarkUserVerifiedUseCase for MarkUserVerifiedService {
             .await
             .unwrap()
         {
-            return Err(IdentityError::VerificationOTPSecretDoesntExist);
+            return Err(IdentityError::VerificationOTPSecretNotFound);
         }
 
         self.db_delete_verification_secret_adapter
@@ -86,7 +86,7 @@ mod tests {
 
             assert_eq!(
                 s.mark_user_verified(cmd.clone()).await.err(),
-                Some(IdentityError::VerificationOTPSecretDoesntExist)
+                Some(IdentityError::VerificationOTPSecretNotFound)
             );
         }
     }
diff --git a/src/identity/application/services/register_user/service.rs b/src/identity/application/services/register_user/service.rs
index 6fd1f64..a858e9e 100644
--- a/src/identity/application/services/register_user/service.rs
+++ b/src/identity/application/services/register_user/service.rs
@@ -13,6 +13,7 @@ use crate::identity::application::port::output::{
 use crate::utils::random_string::*;
 
 pub const SECRET_LEN: usize = 20;
+pub const REGISTRATION_SECRET_PURPOSE: &str = "account_validation";
 
 #[derive(Builder)]
 pub struct RegisterUserService {
@@ -35,7 +36,7 @@ impl RegisterUserUseCase for RegisterUserService {
             .await
             .unwrap()
         {
-            return Err(IdentityError::UsernameExists);
+            return Err(IdentityError::DuplicateUsername);
         }
 
         if self
@@ -44,7 +45,7 @@ impl RegisterUserUseCase for RegisterUserService {
             .await
             .unwrap()
         {
-            return Err(IdentityError::EmailExists);
+            return Err(IdentityError::DuplicateEmail);
         }
 
         let secret = self.random_string_adapter.get_random(SECRET_LEN);
@@ -152,7 +153,7 @@ mod tests {
 
             assert_eq!(
                 s.register_user(cmd.clone()).await.err(),
-                Some(IdentityError::UsernameExists)
+                Some(IdentityError::DuplicateUsername)
             );
         }
 
@@ -182,7 +183,7 @@ mod tests {
 
             assert_eq!(
                 s.register_user(cmd.clone()).await.err(),
-                Some(IdentityError::EmailExists)
+                Some(IdentityError::DuplicateEmail)
             );
         }
     }