diff --git a/src/main/java/entities/Categories.java b/src/main/java/entities/Categories.java
new file mode 100644
index 0000000..43bda11
--- /dev/null
+++ b/src/main/java/entities/Categories.java
@@ -0,0 +1,33 @@
+package entities;
+
+public class Categories {
+
+    public enum ExpenseCategory {
+        CREDIT, BUY, BUSINESS, ENTERTAINMENT, RESTAURANTS_AND_CAFE, COMMUNAL_PAYMENTS, SUPERMARKET, MISC;
+
+        public String getEffectiveName() {
+            return Categories.getEffectiveName(this.name());
+        }
+    }
+
+    public enum IncomeCategory {
+        P2P, SALARY, GIFT, CREDIT, MISC;
+
+        public String getEffectiveName() {
+            return Categories.getEffectiveName(this.name());
+        }
+    }
+
+    private static String getEffectiveName(String name) {
+        String[] arr = name.split("_");
+        StringBuilder result = new StringBuilder();
+        for(String entry : arr) {
+            String[] entryArr = entry.split("");
+            StringBuilder builder = new StringBuilder(entryArr[0]);
+            for(int i = 1; i < entry.length(); i++) builder.append(entryArr[i].toLowerCase());
+            result.append(builder).append(" ");
+        }
+        return result.toString();
+    }
+
+}
diff --git a/src/main/java/entities/Expense.java b/src/main/java/entities/Expense.java
index 606e4eb..c6b2c3b 100644
--- a/src/main/java/entities/Expense.java
+++ b/src/main/java/entities/Expense.java
@@ -1,12 +1,12 @@
 package entities;
 
-public class Expense extends MoneyTransaction {
+public class Expense implements IMoneyTransaction {
 
     private int userId;
     private int amount;
-    private ExpensesCategory category;
+    private Categories.ExpenseCategory category;
 
-    public Expense(int userId, int amount, ExpensesCategory category) {
+    public Expense(int userId, int amount, Categories.ExpenseCategory category) {
         this.userId = userId;
         this.amount = amount;
         this.category = category;
@@ -32,10 +32,10 @@ public class Expense extends MoneyTransaction {
 
     @Override
     public String getCategory() {
-        return category.toString();
+        return category.getEffectiveName();
     }
 
-    public void setCategory(ExpensesCategory category) {
+    public void setCategory(Categories.ExpenseCategory category) {
         this.category = category;
     }
 }
diff --git a/src/main/java/entities/ExpensesCategory.java b/src/main/java/entities/ExpensesCategory.java
deleted file mode 100644
index bf76cc7..0000000
--- a/src/main/java/entities/ExpensesCategory.java
+++ /dev/null
@@ -1,5 +0,0 @@
-package entities;
-
-public enum ExpensesCategory {
-    MISC;
-}
diff --git a/src/main/java/entities/IMoneyTransaction.java b/src/main/java/entities/IMoneyTransaction.java
new file mode 100644
index 0000000..70b92d5
--- /dev/null
+++ b/src/main/java/entities/IMoneyTransaction.java
@@ -0,0 +1,9 @@
+package entities;
+
+public interface IMoneyTransaction {
+
+    long getUserId();
+    int getAmount();
+    String getCategory();
+
+}
diff --git a/src/main/java/entities/Income.java b/src/main/java/entities/Income.java
index f3edc27..31b5d67 100644
--- a/src/main/java/entities/Income.java
+++ b/src/main/java/entities/Income.java
@@ -1,12 +1,12 @@
 package entities;
 
-public class Income extends MoneyTransaction {
+public class Income implements IMoneyTransaction {
 
     private long userId;
     private int amount;
-    private IncomeCategory category;
+    private Categories.IncomeCategory category;
 
-    public Income(long userId, int amount, IncomeCategory category) {
+    public Income(long userId, int amount, Categories.IncomeCategory category) {
         this.userId = userId;
         this.amount = amount;
         this.category = category;
@@ -24,7 +24,7 @@ public class Income extends MoneyTransaction {
 
     @Override
     public String getCategory() {
-        return category.toString();
+        return category.getEffectiveName();
     }
 
     public void setUserId(long userId) {
@@ -35,7 +35,7 @@ public class Income extends MoneyTransaction {
         this.amount = amount;
     }
 
-    public void setCategory(IncomeCategory category) {
+    public void setCategory(Categories.IncomeCategory category) {
         this.category = category;
     }
 }
diff --git a/src/main/java/entities/IncomeCategory.java b/src/main/java/entities/IncomeCategory.java
deleted file mode 100644
index 7d1666c..0000000
--- a/src/main/java/entities/IncomeCategory.java
+++ /dev/null
@@ -1,5 +0,0 @@
-package entities;
-
-public enum IncomeCategory {
-    MISC;
-}
diff --git a/src/main/java/entities/MoneyTransaction.java b/src/main/java/entities/MoneyTransaction.java
deleted file mode 100644
index 2232df4..0000000
--- a/src/main/java/entities/MoneyTransaction.java
+++ /dev/null
@@ -1,9 +0,0 @@
-package entities;
-
-public abstract class MoneyTransaction {
-
-    public abstract long getUserId();
-    public abstract int getAmount();
-    public abstract String getCategory();
-
-}