diff --git a/src/db/_accounts.rs b/src/db/_accounts.rs
index 2c51fea..fd26775 100644
--- a/src/db/_accounts.rs
+++ b/src/db/_accounts.rs
@@ -5,7 +5,7 @@ use crate::db::_external_id::{AccountId, Id, UserId};
 use crate::db::_securities::Security;
 use crate::db::_users::User;
 use crate::db::external_id::SecurityId;
-use crate::util::{CustomResult, Error, TransactionHelper};
+use crate::util::{CustomResult, Error};
 
 #[derive(PartialEq, Debug)]
 pub enum AccountType {
diff --git a/src/db/_cheques.rs b/src/db/_cheques.rs
index ad9e1b8..0b60a5f 100644
--- a/src/db/_cheques.rs
+++ b/src/db/_cheques.rs
@@ -6,7 +6,7 @@ pub type Drawer = (UserId, AccountId, SecurityId);
 pub type Payee = (UserId, SecurityId);
 
 #[derive(Debug)]
-pub struct SecurityEmitterCheque {
+pub struct Cheque {
     pub drawer_user_id: UserId,
     pub drawer_account_id: AccountId,
     pub security_id: SecurityId,
@@ -15,12 +15,12 @@ pub struct SecurityEmitterCheque {
     pub amount: i64,
 }
 
-impl SecurityEmitterCheque {
+impl Cheque {
     pub fn new(drawer: Drawer,
                payee: Payee,
                amount: i64,
-               cheque_number: i64) -> SecurityEmitterCheque {
-        SecurityEmitterCheque {
+               cheque_number: i64) -> Cheque {
+        Cheque {
             drawer_user_id: drawer.0,
             drawer_account_id: drawer.1,
             security_id: drawer.2,
@@ -30,11 +30,3 @@ impl SecurityEmitterCheque {
         }
     }
 }
-
-#[cfg(test)]
-pub mod test {
-    use super::*;
-
-    #[test]
-    fn test_foo() {}
-}
\ No newline at end of file
diff --git a/src/db/_interests.rs b/src/db/_interests.rs
new file mode 100644
index 0000000..139597f
--- /dev/null
+++ b/src/db/_interests.rs
@@ -0,0 +1,2 @@
+
+
diff --git a/src/db/mod.rs b/src/db/mod.rs
index 98131e1..cf98e4c 100644
--- a/src/db/mod.rs
+++ b/src/db/mod.rs
@@ -4,6 +4,7 @@ mod _accounts;
 mod _cheques;
 mod _external_id;
 mod _test_utils;
+mod _interests;
 
 pub mod external_id {
     pub use super::_external_id::*;
@@ -28,7 +29,7 @@ pub mod accounts {
 }
 
 pub mod cheques {
-    pub use super::_cheques::{SecurityEmitterCheque, Drawer, Payee};
+    pub use super::_cheques::{Cheque, Drawer, Payee};
 }
 
 pub mod test_utils {
diff --git a/src/main.rs b/src/main.rs
index 8e42610..054f9f2 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -162,7 +162,7 @@ fn process_command_line(conn: &mut Connection, m: &ArgMatches, logic: &mut dyn C
 }
 
 #[cfg(test)]
-mod test {
+mod cli_test {
     use super::*;
 
     struct TestCommandLineLogic {
diff --git a/src/services/_transactions.rs b/src/services/_transactions.rs
index 10b61cd..8ce661a 100644
--- a/src/services/_transactions.rs
+++ b/src/services/_transactions.rs
@@ -2,13 +2,13 @@ use rusqlite::{Connection, ffi, params, Params, Savepoint, Transaction};
 
 use crate::db::{accounts, securities};
 use crate::db::accounts::{Account, get_account_by_id};
-use crate::db::cheques::SecurityEmitterCheque;
+use crate::db::cheques::Cheque;
 use crate::db::external_id::AccountId;
 use crate::db::securities::get_security_by_id;
 use crate::util::*;
 
 fn _move_securities(tx: &Savepoint,
-                    cheque: &SecurityEmitterCheque,
+                    cheque: &Cheque,
                     account_id: &AccountId) -> CustomResult<()> {
     let drawer_receipt = accounts::add_to_account(tx, &cheque.drawer_account_id, -cheque.amount)?;
     let payee_receipt = accounts::add_to_account(tx, account_id, cheque.amount)?;
@@ -20,7 +20,7 @@ fn _move_securities(tx: &Savepoint,
 }
 
 fn _add_cheque_to_cashed_cheques_log(tx: &Connection,
-                                     cheque: &SecurityEmitterCheque,
+                                     cheque: &Cheque,
                                      account_id: &AccountId) -> Result<(), Error> {
     let q = "
         INSERT INTO cashed_cheques(
@@ -44,7 +44,7 @@ fn _add_cheque_to_cashed_cheques_log(tx: &Connection,
 }
 
 fn cash_cheque_unsafe(savepoint: &Savepoint,
-                      cheque: &SecurityEmitterCheque,
+                      cheque: &Cheque,
                       account_id: &AccountId) -> CustomResult<()> {
     if cheque.amount < 0 {
         return Err(Error::InvalidAmount(format!("The cheque {:?} has a negative amount.", cheque)));
@@ -63,7 +63,7 @@ fn cash_cheque_unsafe(savepoint: &Savepoint,
 }
 
 fn cash_cheque(tx: &mut Transaction,
-               cheque: &SecurityEmitterCheque,
+               cheque: &Cheque,
                account_id: &AccountId) -> CustomResult<()> {
     let mut savepoint = tx.savepoint().map_err(Error::SqlError)?;
     let ret = cash_cheque_unsafe(&savepoint, cheque, account_id);
@@ -98,30 +98,57 @@ mod test_caching_cheques {
         return conn;
     }
 
-    fn setup_basic() -> (Connection, Drawer, Payee, AccountId) {
+    fn setup_security_emitter() -> (Connection, Drawer, Payee, AccountId) {
         let mut conn = setup_conn();
         let tx = conn.transaction().unwrap();
         let (users, securities, accounts) = test_utils::setup_basic_environment(&tx).unwrap();
         let sec = securities.get(0).unwrap();
         let drawer = users.get(0).unwrap();
         let payee = users.get(1).unwrap();
-        let drawer_account = create_security_emitter_account(&tx, &sec.id(), &drawer.id()).unwrap();
+        let security_emitter_account = create_security_emitter_account(&tx, &sec.id(), &drawer.id()).unwrap();
         let payee_account = create_checking_account(&tx, &sec.id(), &payee.id()).unwrap();
 
         tx.commit().unwrap();
-        let drawer: Drawer = (drawer.id(), drawer_account.id(), sec.id());
+        let security_emitter: Drawer = (drawer.id(), security_emitter_account.id(), sec.id());
         let payee: Payee = (payee.id(), sec.id());
-        (conn, drawer, payee, payee_account.id())
+        (conn, security_emitter, payee, payee_account.id())
+    }
+
+    fn _create_100_secs_in_payee_account(tx: &mut Transaction, security_emitter: &Drawer, payee: &Payee, payee_account: &AccountId) {
+        let cheque = Cheque::new(
+            security_emitter.clone(), payee.clone(), 100, 99);
+
+        cash_cheque(tx, &cheque, &payee_account).unwrap();
+    }
+
+    fn _create_drawer(payee: Payee, payee_account: AccountId) -> Drawer {
+        (payee.0, payee_account, payee.1)
+    }
+
+    fn setup_basic() -> (Connection, Drawer, Payee, AccountId) {
+        let (mut conn, security_emitter, payee, payee_account) = setup_security_emitter();
+
+        let mut tx = conn.transaction().unwrap();
+
+        _create_100_secs_in_payee_account(&mut tx, &security_emitter, &payee, &payee_account);
+        let reg_account = create_checking_account(&tx, &security_emitter.2, &security_emitter.0).unwrap();
+
+        tx.commit().unwrap();
+
+        let drawer: Drawer = _create_drawer(payee, payee_account);
+        let new_payee: Payee = (security_emitter.0, security_emitter.2);
+
+        return (conn, drawer, new_payee, reg_account.id())
     }
 
 
     #[test]
-    fn test_basic_happy_path() -> CustomResult<()> {
-        let (mut conn, drawer, payee, payee_account) = setup_basic();
+    fn test_happy_path_currency_emitter() -> CustomResult<()> {
+        let (mut conn, security_emitter, payee, payee_account) = setup_security_emitter();
         let mut tx = conn.transaction().unwrap();
 
-        let cheque = SecurityEmitterCheque::new(
-            drawer, payee, 1000, 99);
+        let cheque = Cheque::new(
+            security_emitter, payee, 1000, 99);
 
         cash_cheque(&mut tx, &cheque, &payee_account)?;
         tx.commit().unwrap();
@@ -134,30 +161,56 @@ mod test_caching_cheques {
     }
 
     #[test]
-    fn test_negative_cheque() -> CustomResult<()> {
+    fn test_happy_path_regular_cheque() -> CustomResult<()> {
         let (mut conn, drawer, payee, payee_account) = setup_basic();
         let mut tx = conn.transaction().unwrap();
 
-        let cheque = SecurityEmitterCheque::new(
-            drawer, payee, -1000, 99);
+        let cheque = Cheque::new(
+            drawer.clone(), payee, 25, 10001);
+
+        cash_cheque(&mut tx, &cheque, &payee_account)?;
+
+        let payee_acc = get_account_by_id(&tx, &payee_account).unwrap();
+        assert_eq!(payee_acc.raw_amount(), 25);
+
+        let drawer_acc = get_account_by_id(&tx, &drawer.1).unwrap();
+        assert_eq!(drawer_acc.raw_amount(), 75);
+
+        Ok(())
+    }
+
+    fn test_negative_cheque(conn: &mut Connection, drawer: Drawer, payee: Payee, payee_account: AccountId) -> CustomResult<()> {
+        let mut tx = conn.transaction().unwrap();
+
+        let cheque = Cheque::new(
+            drawer, payee, -1, 99);
 
         let ret = cash_cheque(&mut tx, &cheque, &payee_account);
         match ret {
             Err(Error::InvalidAmount(_)) => Ok(()),
-            _ => Err(Error::Testing("Expected double spending error here.".to_string()))
+            _ => Err(Error::Testing("Expected invalid amount error here.".to_string()))
         }
     }
 
     #[test]
-    fn test_double_spend() -> CustomResult<()> {
+    fn test_negative_security_emitter_cheque() -> CustomResult<()> {
+        let (mut conn, security_emitter, payee, payee_account) = setup_security_emitter();
+        test_negative_cheque(&mut conn, security_emitter, payee, payee_account)
+    }
+
+    #[test]
+    fn test_negative_regular_cheque() -> CustomResult<()> {
         let (mut conn, drawer, payee, payee_account) = setup_basic();
-        let amount = 1000;
+        test_negative_cheque(&mut conn, drawer, payee, payee_account)
+    }
+
+    fn test_double_spend(conn: &mut Connection, drawer: Drawer, payee: Payee, payee_account: AccountId) -> CustomResult<()> {
         let mut tx = conn.transaction().unwrap();
 
-        let cheque = SecurityEmitterCheque::new(
+        let cheque = Cheque::new(
             drawer,
             payee,
-            1000,
+            10,
             99,
         );
 
@@ -173,16 +226,25 @@ mod test_caching_cheques {
     }
 
     #[test]
-    fn test_invalid_drawer() -> CustomResult<()> {
+    fn test_double_spend_security_emitter_cheque() -> CustomResult<()> {
+        let (mut conn, security_emitter, payee, payee_account) = setup_security_emitter();
+        test_double_spend(&mut conn, security_emitter, payee, payee_account)
+    }
+
+    #[test]
+    fn test_double_spend_regular_emitter_cheque() -> CustomResult<()> {
         let (mut conn, drawer, payee, payee_account) = setup_basic();
-        let amount = 1000;
+        test_double_spend(&mut conn, drawer, payee, payee_account)
+    }
+
+    fn test_invalid_drawer(conn: &mut Connection, drawer: Drawer, payee: Payee, payee_account: AccountId) -> CustomResult<()> {
         let mut tx = conn.transaction().unwrap();
         let not_currency_owner_user_id = UserId::from_id(drawer.0.get_id() + 72623);
         let not_currency_owner: Drawer = (not_currency_owner_user_id, drawer.1, drawer.2);
-        let cheque = SecurityEmitterCheque::new(
+        let cheque = Cheque::new(
             not_currency_owner,
             payee,
-            1000,
+            100,
             99,
         );
 
@@ -194,14 +256,24 @@ mod test_caching_cheques {
     }
 
     #[test]
-    fn test_invalid_payee() -> CustomResult<()> {
-        let (mut conn, drawer, payee, payee_account) = setup_basic();
-        let mut tx = conn.transaction().unwrap();
-        // let wrong_payee_account = create_checking_account(&tx, &sec.id(), &payee.id()).unwrap();
-        let wrong_payee_account = &drawer.1;
+    fn test_invalid_drawer_security_emitter() -> CustomResult<()> {
+        let (mut conn, security_emitter, payee, payee_account) = setup_security_emitter();
+        test_invalid_drawer(&mut conn, security_emitter, payee, payee_account)
+    }
 
-        let cheque = SecurityEmitterCheque::new(
-            drawer.clone(), payee.clone(), 1000, 99);
+    #[test]
+    fn test_invalid_drawer_regular_cheque() -> CustomResult<()> {
+        let (mut conn, drawer, payee, payee_account) = setup_basic();
+        test_invalid_drawer(&mut conn, drawer, payee, payee_account)
+    }
+
+    fn test_invalid_payee(conn: &mut Connection, security_emitter: Drawer, payee: Payee, payee_account: AccountId) -> CustomResult<()> {
+        let (mut conn, security_emitter, payee, payee_account) = setup_security_emitter();
+        let mut tx = conn.transaction().unwrap();
+        let wrong_payee_account = &security_emitter.1;
+
+        let cheque = Cheque::new(
+            security_emitter.clone(), payee.clone(), 1000, 99);
 
         let ret = cash_cheque(&mut tx, &cheque, wrong_payee_account);
         match ret {
@@ -209,4 +281,17 @@ mod test_caching_cheques {
             _ => Err(Error::Testing("Expected invalid payee here.".to_string()))
         }
     }
+
+
+    #[test]
+    fn test_invalid_payee_security_emitter_cheque() -> CustomResult<()> {
+        let (mut conn, security_emitter, payee, payee_account) = setup_security_emitter();
+        test_invalid_payee(&mut conn, security_emitter, payee, payee_account)
+    }
+
+    #[test]
+    fn test_invalid_payee_regular_cheque() -> CustomResult<()> {
+        let (mut conn, drawer, payee, payee_account) = setup_basic();
+        test_invalid_payee(&mut conn, drawer, payee, payee_account)
+    }
 }
\ No newline at end of file