diff --git a/Diagram.png b/Diagram.png
new file mode 100644
index 000000000..605b224bb
Binary files /dev/null and b/Diagram.png differ
diff --git a/src/main/java/com/booleanuk/core/.gitkeep b/domain-model.md
similarity index 100%
rename from src/main/java/com/booleanuk/core/.gitkeep
rename to domain-model.md
diff --git a/src/main/java/com/booleanuk/core/Account.java b/src/main/java/com/booleanuk/core/Account.java
new file mode 100644
index 000000000..c39b3e2e4
--- /dev/null
+++ b/src/main/java/com/booleanuk/core/Account.java
@@ -0,0 +1,103 @@
+package com.booleanuk.core;
+
+import java.time.LocalDate;
+import java.time.format.DateTimeFormatter;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.UUID;
+
+public abstract class Account {
+    private UUID id;
+    private UUID CustomerUUID;
+    private List<Transaction> transactions;
+    private AccountType accountType;
+
+    public Account(UUID CustomerUUID, AccountType accountType) {
+        this.id = UUID.randomUUID();
+        this.CustomerUUID = CustomerUUID;
+        this.transactions = new ArrayList<Transaction>();
+        this.accountType = accountType;
+    }
+
+    public void addTransaction(double amount) {
+        this.transactions.add(new Transaction(amount));
+    }
+
+    public double calculateBalance() {
+        return transactions.stream().mapToDouble(Transaction::getAmount).sum();
+    }
+
+    public UUID getId() {
+        return id;
+    }
+
+    public void setId(UUID id) {
+        this.id = id;
+    }
+
+    public UUID getCustomerUUID() {
+        return CustomerUUID;
+    }
+
+    public void setCustomerUUID(UUID customerUUID) {
+        CustomerUUID = customerUUID;
+    }
+
+    public List<Transaction> getTransactions() {
+        return transactions;
+    }
+
+    public void setTransactions(List<Transaction> transactions) {
+        this.transactions = transactions;
+    }
+
+    public AccountType getAccountType() {
+        return accountType;
+    }
+
+    public void setAccountType(AccountType accountType) {
+        this.accountType = accountType;
+    }
+
+    @Override
+    public String toString() {
+        return "Account{" +
+                "id=" + id +
+                ", CustomerUUID=" + CustomerUUID +
+                ", transactions=" + transactions +
+                ", accountType=" + accountType +
+               '}';
+    }
+
+    public void printAccountStatement() {
+
+        final String rowFmt = "%-15s||%15s||%15s||%15s%n";
+        System.out.printf(rowFmt,"date", "credit", "debit", "balance");
+
+        // Date Innskudd Utrekk Balanse
+        double balance = 0;
+
+        for (Transaction transaction : transactions) {
+            String transactionDate =  transaction.getDate().toString();
+            double amount = transaction.getAmount();
+            String credit = "";
+            String debit = "";
+
+            if(amount <= 0) {
+                debit = Double.toString(
+                        Math.abs(amount));
+            }
+            else{
+                credit = Double.toString(
+                        amount);
+            }
+
+            balance = balance + amount;
+
+            System.out.printf(rowFmt,transactionDate, credit, debit, balance);
+
+        }
+    }
+}
+
diff --git a/src/main/java/com/booleanuk/core/AccountType.java b/src/main/java/com/booleanuk/core/AccountType.java
new file mode 100644
index 000000000..9262aef86
--- /dev/null
+++ b/src/main/java/com/booleanuk/core/AccountType.java
@@ -0,0 +1,6 @@
+package com.booleanuk.core;
+
+public enum AccountType {
+    CURRENT,
+    SAVINGS
+}
diff --git a/src/main/java/com/booleanuk/core/BankManager.java b/src/main/java/com/booleanuk/core/BankManager.java
new file mode 100644
index 000000000..33c5339a6
--- /dev/null
+++ b/src/main/java/com/booleanuk/core/BankManager.java
@@ -0,0 +1,10 @@
+package com.booleanuk.core;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class BankManager {
+    private String name;
+    private ArrayList<String> branchUUIDs;
+
+}
\ No newline at end of file
diff --git a/src/main/java/com/booleanuk/core/Branch.java b/src/main/java/com/booleanuk/core/Branch.java
new file mode 100644
index 000000000..b081398ec
--- /dev/null
+++ b/src/main/java/com/booleanuk/core/Branch.java
@@ -0,0 +1,37 @@
+package com.booleanuk.core;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
+
+public class Branch {
+    private List<Account> accounts;
+    private UUID id;
+    private String name;
+
+    public Branch(String name) {
+        this.name = name;
+        this.accounts = new ArrayList<Account>();
+        this.id = UUID.randomUUID();
+    }
+
+    public void createSavingsAccountForUser(UUID customerId) {
+        this.accounts.add(new SavingsAccount(customerId));
+    }
+
+    public void createCurrentAccountForUser(UUID customerId) {
+        this.accounts.add(new CurrentAccount(customerId));
+    }
+
+    public List<Account> getAccountsForCustomerID(UUID customerId) {
+        return this.accounts.stream()
+                .filter(account -> account.getCustomerUUID().equals(customerId))
+                .toList();
+    }
+
+    public List<Account> getAccountsForAccountID(UUID accountID) {
+        return this.accounts.stream()
+                .filter(account -> account.getId().equals(accountID))
+                .toList();
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/com/booleanuk/core/CurrentAccount.java b/src/main/java/com/booleanuk/core/CurrentAccount.java
new file mode 100644
index 000000000..2e055e25c
--- /dev/null
+++ b/src/main/java/com/booleanuk/core/CurrentAccount.java
@@ -0,0 +1,33 @@
+package com.booleanuk.core;
+
+import java.util.UUID;
+import com.booleanuk.core.AccountType;
+
+public class CurrentAccount extends Account {
+    private static final AccountType accountType = AccountType.CURRENT;
+    private double overdraftLimit;
+    private boolean overdraftApproved;
+
+    public CurrentAccount(UUID CustomerUUID) {
+        super(CustomerUUID, accountType);
+        this.overdraftLimit = 0;
+        this.overdraftApproved = false;
+    }
+
+    public double getOverdraftLimit() {
+        return overdraftLimit;
+    }
+
+    public void setOverdraftLimit(double overdraftLimit) {
+        this.overdraftApproved = false;
+        this.overdraftLimit = overdraftLimit;
+    }
+
+    public boolean isOverdraftApproved() {
+        return overdraftApproved;
+    }
+
+    public void setOverdraftApproved(boolean overdraftApproved) {
+        this.overdraftApproved = overdraftApproved;
+    }
+}
diff --git a/src/main/java/com/booleanuk/core/Customer.java b/src/main/java/com/booleanuk/core/Customer.java
new file mode 100644
index 000000000..af9a4c560
--- /dev/null
+++ b/src/main/java/com/booleanuk/core/Customer.java
@@ -0,0 +1,22 @@
+package com.booleanuk.core;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
+
+public class Customer extends User {
+
+    private List<UUID> accountUUIDs;
+    public Customer(String name) {
+        super(name);
+        this.accountUUIDs = new ArrayList<UUID>();
+    }
+
+    public List<UUID> getAccountUUIDs() {
+        return accountUUIDs;
+    }
+
+    public void addAccount(UUID accountUUID) {
+        this.accountUUIDs.add(accountUUID);
+    }
+}
diff --git a/src/main/java/com/booleanuk/core/SavingsAccount.java b/src/main/java/com/booleanuk/core/SavingsAccount.java
new file mode 100644
index 000000000..7c991dc9b
--- /dev/null
+++ b/src/main/java/com/booleanuk/core/SavingsAccount.java
@@ -0,0 +1,13 @@
+package com.booleanuk.core;
+
+import java.util.UUID;
+
+public class SavingsAccount extends Account {
+    private float interestRate;
+    private static final AccountType accountType = AccountType.SAVINGS;
+
+    public SavingsAccount(UUID CustomerUUID) {
+        super(CustomerUUID, accountType);
+        this.interestRate = 0;
+    }
+}
diff --git a/src/main/java/com/booleanuk/core/Transaction.java b/src/main/java/com/booleanuk/core/Transaction.java
new file mode 100644
index 000000000..fce6704b8
--- /dev/null
+++ b/src/main/java/com/booleanuk/core/Transaction.java
@@ -0,0 +1,40 @@
+package com.booleanuk.core;
+
+import java.time.LocalDate;
+import java.util.UUID;
+
+public class Transaction {
+    private double amount;
+    private LocalDate date;
+    private UUID id;
+
+    public Transaction(double amount) {
+        this.date = LocalDate.now();
+        this.amount = amount;
+        this.id = UUID.randomUUID();
+    }
+
+    public double getAmount() {
+        return amount;
+    }
+
+    public void setAmount(float amount) {
+        this.amount = amount;
+    }
+
+    public LocalDate getDate() {
+        return date;
+    }
+
+    public void setDate(LocalDate date) {
+        this.date = date;
+    }
+
+    public UUID getId() {
+        return id;
+    }
+
+    public void setId(UUID id) {
+        this.id = id;
+    }
+}
diff --git a/src/main/java/com/booleanuk/core/User.java b/src/main/java/com/booleanuk/core/User.java
new file mode 100644
index 000000000..312db0f41
--- /dev/null
+++ b/src/main/java/com/booleanuk/core/User.java
@@ -0,0 +1,29 @@
+package com.booleanuk.core;
+
+import java.util.UUID;
+
+public abstract class User {
+    private UUID uuid;
+    private String name;
+
+    public User(String name) {
+        this.uuid = java.util.UUID.randomUUID();
+        this.name = name;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public UUID getUUID() {
+        return uuid;
+    }
+
+    public void setUUID(UUID uuid) {
+        this.uuid = uuid;
+    }
+}
diff --git a/src/test/java/com/booleanuk/core/.gitkeep b/src/test/java/com/booleanuk/core/.gitkeep
deleted file mode 100644
index e69de29bb..000000000
diff --git a/src/test/java/com/booleanuk/core/AccountTest.java b/src/test/java/com/booleanuk/core/AccountTest.java
new file mode 100644
index 000000000..520cd8e74
--- /dev/null
+++ b/src/test/java/com/booleanuk/core/AccountTest.java
@@ -0,0 +1,39 @@
+package com.booleanuk.core;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+import java.util.UUID;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class AccountTest {
+
+    @Test
+    public void addTransaction() {
+        Branch testBranch = new Branch("oslo");
+        User testCustomer = new Customer("Trond Giske");
+        UUID testUserUUID = testCustomer.getUUID();
+
+        testBranch.createCurrentAccountForUser(testUserUUID);
+        Account testAccount = testBranch.getAccountsForCustomerID(testUserUUID).getFirst();
+        testAccount.addTransaction(1000.99);
+        Transaction testTransaction = testAccount.getTransactions().getFirst();
+
+        assertEquals(1000.99, testTransaction.getAmount());
+    }
+
+    @Test
+    public void calculateBalance() {
+        Branch testBranch = new Branch("oslo");
+        User testCustomer = new Customer("Trond Giske");
+        UUID testUserUUID = testCustomer.getUUID();
+
+        testBranch.createCurrentAccountForUser(testUserUUID);
+        Account testAccount = testBranch.getAccountsForCustomerID(testUserUUID).getFirst();
+        testAccount.addTransaction(1000.99);
+        testAccount.addTransaction(1000.99);
+
+        assertEquals(2001.98, testAccount.calculateBalance());
+    }
+}
diff --git a/src/test/java/com/booleanuk/core/BankManagerTest.java b/src/test/java/com/booleanuk/core/BankManagerTest.java
new file mode 100644
index 000000000..3c310f4f0
--- /dev/null
+++ b/src/test/java/com/booleanuk/core/BankManagerTest.java
@@ -0,0 +1,13 @@
+package com.booleanuk.core;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class BankManagerTest {
+    @Test
+    public void testBankManager() {
+        // Nothing to test here except getters and setters
+        assertTrue(true);
+    }
+}
diff --git a/src/test/java/com/booleanuk/core/BranchTest.java b/src/test/java/com/booleanuk/core/BranchTest.java
new file mode 100644
index 000000000..0290d76c4
--- /dev/null
+++ b/src/test/java/com/booleanuk/core/BranchTest.java
@@ -0,0 +1,74 @@
+package com.booleanuk.core;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+import java.util.UUID;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class BranchTest {
+
+    @Test
+    public void createSavingsAccountForUser() {
+        Branch testBranch = new Branch("oslo");
+        User testCustomer = new Customer("Trond Giske");
+
+        testBranch.createSavingsAccountForUser(testCustomer.getUUID());
+        testBranch.getAccountsForCustomerID(testCustomer.getUUID());
+    }
+
+    @Test
+    public void createCurrentAccountForUser() {
+        Branch testBranch = new Branch("oslo");
+        User testCustomer = new Customer("Trond Giske");
+
+        testBranch.createCurrentAccountForUser(testCustomer.getUUID());
+
+        assertNotNull(testBranch.getAccountsForCustomerID(testCustomer.getUUID()));
+    }
+
+    @Test
+    public void getAccountsForCustomerID() {
+        Branch testBranch = new Branch("oslo");
+        User testCustomer = new Customer("Trond Giske");
+        UUID testUserUUID = testCustomer.getUUID();
+
+        testBranch.createCurrentAccountForUser(testUserUUID);
+
+        assertNotNull(testBranch.getAccountsForCustomerID(testUserUUID));
+    }
+
+    @Test
+    public void getAccountsForAccountID() {
+        Branch testBranch = new Branch("oslo");
+        User testCustomer = new Customer("Trond Giske");
+        UUID testUserUUID = testCustomer.getUUID();
+
+        testBranch.createCurrentAccountForUser(testUserUUID);
+
+        List<Account> testAccount = testBranch.getAccountsForCustomerID(testUserUUID);
+        UUID testAccountUUID = testAccount.getFirst().getId();
+
+        assertNotNull(testBranch.getAccountsForAccountID(testAccountUUID));
+    }
+
+    @Test void testEverything() {
+        Branch testBranch = new Branch("oslo");
+        User testCustomer = new Customer("Trond Giske");
+        UUID testUserUUID = testCustomer.getUUID();
+
+        testBranch.createCurrentAccountForUser(testUserUUID);
+        CurrentAccount testAccount = (CurrentAccount) testBranch.getAccountsForCustomerID(testUserUUID).getFirst();
+
+        testAccount.addTransaction(1000);
+        testAccount.addTransaction(2000);
+        testAccount.addTransaction(-500);
+
+        testAccount.printAccountStatement();
+
+        assertEquals(2500, testAccount.calculateBalance());
+
+
+    }
+}
diff --git a/src/test/java/com/booleanuk/core/CurrentAccountTest.java b/src/test/java/com/booleanuk/core/CurrentAccountTest.java
new file mode 100644
index 000000000..a3ebcca88
--- /dev/null
+++ b/src/test/java/com/booleanuk/core/CurrentAccountTest.java
@@ -0,0 +1,29 @@
+package com.booleanuk.core;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.UUID;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class CurrentAccountTest {
+
+    @Test
+    public void testOverdraftLimit() {
+        Branch testBranch = new Branch("oslo");
+        User testCustomer = new Customer("Trond Giske");
+        UUID testUserUUID = testCustomer.getUUID();
+
+        testBranch.createCurrentAccountForUser(testUserUUID);
+        CurrentAccount testAccount = (CurrentAccount) testBranch.getAccountsForCustomerID(testUserUUID).getFirst();
+
+        testAccount.setOverdraftLimit(222);
+        assertEquals(222, testAccount.getOverdraftLimit());
+
+        testAccount.setOverdraftApproved(true);
+        assertTrue(testAccount.isOverdraftApproved());
+
+        testAccount.setOverdraftLimit(333);
+        assertFalse(testAccount.isOverdraftApproved());
+    }
+}
diff --git a/src/test/java/com/booleanuk/core/CustomerTest.java b/src/test/java/com/booleanuk/core/CustomerTest.java
new file mode 100644
index 000000000..5c7b385c2
--- /dev/null
+++ b/src/test/java/com/booleanuk/core/CustomerTest.java
@@ -0,0 +1,13 @@
+package com.booleanuk.core;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class CustomerTest {
+    @Test
+    public void testCustomer() {
+        // Nothing to test here except getters and setters
+        assertTrue(true);
+    }
+}
diff --git a/src/test/java/com/booleanuk/core/SavingsAccountTest.java b/src/test/java/com/booleanuk/core/SavingsAccountTest.java
new file mode 100644
index 000000000..fb64b3e7c
--- /dev/null
+++ b/src/test/java/com/booleanuk/core/SavingsAccountTest.java
@@ -0,0 +1,26 @@
+package com.booleanuk.core;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.UUID;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class SavingsAccountTest {
+
+    @Test
+    public void testSavingsAccount() {
+        // Didn't get around to implement interest rate
+        // The class should behave the same way that current account works, with the accountType field set to 'SAVINGS'
+
+        Branch testBranch = new Branch("oslo");
+        User testCustomer = new Customer("Trond Giske");
+        UUID testUserUUID = testCustomer.getUUID();
+
+        testBranch.createSavingsAccountForUser(testUserUUID);
+        SavingsAccount testAccount = (SavingsAccount) testBranch.getAccountsForCustomerID(testUserUUID).getFirst();
+
+        assertEquals(AccountType.SAVINGS, testAccount.getAccountType());
+    }
+}
diff --git a/src/test/java/com/booleanuk/core/TransactionTest.java b/src/test/java/com/booleanuk/core/TransactionTest.java
new file mode 100644
index 000000000..e94706ea5
--- /dev/null
+++ b/src/test/java/com/booleanuk/core/TransactionTest.java
@@ -0,0 +1,14 @@
+package com.booleanuk.core;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class TransactionTest {
+
+    @Test
+    public void testTransaction() {
+        // Nothing to test here except getters and setters
+        assertTrue(true);
+    }
+}
diff --git a/src/test/java/com/booleanuk/core/UserTest.java b/src/test/java/com/booleanuk/core/UserTest.java
new file mode 100644
index 000000000..ea81aaaf5
--- /dev/null
+++ b/src/test/java/com/booleanuk/core/UserTest.java
@@ -0,0 +1,13 @@
+package com.booleanuk.core;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class UserTest {
+    @Test
+    public void testUser() {
+        // Nothing to test here except getters and setters
+        assertTrue(true);
+    }
+}