diff --git a/build.gradle b/build.gradle
index 08e9d80a46..b5763d7db6 100644
--- a/build.gradle
+++ b/build.gradle
@@ -42,5 +42,6 @@ checkstyle {
 }
 
 run{
+//    enableAssertions = true
     standardInput = System.in
 }
diff --git a/src/main/java/budgetbuddy/BudgetBuddy.java b/src/main/java/budgetbuddy/BudgetBuddy.java
index f7ece6c633..79d57211bf 100644
--- a/src/main/java/budgetbuddy/BudgetBuddy.java
+++ b/src/main/java/budgetbuddy/BudgetBuddy.java
@@ -18,11 +18,8 @@ public class BudgetBuddy {
     public static void main(String[] args) {
         String logo = "BUDGET BUDDY";
         System.out.println("Hello from\n" + logo);
-        System.out.println("What is your name?");
-
+        System.out.println("What can I do for you?");
         Scanner in = new Scanner(System.in);
-        System.out.println("Hello " + in.nextLine());
-
 
         TransactionList transactions = null;
         try {
diff --git a/src/main/java/budgetbuddy/parser/Parser.java b/src/main/java/budgetbuddy/parser/Parser.java
index c0c85fbd15..6b75a99408 100644
--- a/src/main/java/budgetbuddy/parser/Parser.java
+++ b/src/main/java/budgetbuddy/parser/Parser.java
@@ -29,8 +29,7 @@ public Transaction parseTransaction(String input, Account account)
                 description = parseData[i + 1].trim();
                 break;
             case "$":
-                // Checks that input is an Integer
-                if (!TransactionList.isInteger(parseData[i+1].trim())) {
+                if (TransactionList.isNotDouble(parseData[i + 1].trim())) {
                     throw new NumberFormatException(parseData[i+1].trim());
                 } else {
                     amount = parseData[i + 1].trim();
diff --git a/src/main/java/budgetbuddy/storage/DataStorage.java b/src/main/java/budgetbuddy/storage/DataStorage.java
index 59eb8a4605..88f55a588f 100644
--- a/src/main/java/budgetbuddy/storage/DataStorage.java
+++ b/src/main/java/budgetbuddy/storage/DataStorage.java
@@ -61,7 +61,7 @@ private Transaction processData(String s, Account account) {
             return new Income(transactionInfo[0], Double.parseDouble(transactionInfo[4]),
                     transactionInfo[1], transactionInfo[3], account);
         case "Expense":
-            return new Expense(transactionInfo[0], Double.parseDouble(transactionInfo[4]),
+            return new Expense(transactionInfo[0], -Double.parseDouble(transactionInfo[4]),
                     transactionInfo[1], transactionInfo[3], account);
         default:
             return null;
diff --git a/src/main/java/budgetbuddy/transaction/TransactionList.java b/src/main/java/budgetbuddy/transaction/TransactionList.java
index 92e03cb2bd..2e0ad9cab4 100644
--- a/src/main/java/budgetbuddy/transaction/TransactionList.java
+++ b/src/main/java/budgetbuddy/transaction/TransactionList.java
@@ -43,7 +43,7 @@ public void removeTransaction(String input, Account account) throws EmptyArgumen
             throw new EmptyArgumentException("delete index");
         }
         String data = input.substring(DELETE_BEGIN_INDEX).trim();
-        if (!isInteger(data)) {
+        if (isNotInteger(data)) {
             throw new NumberFormatException(data);
         }
         int id = Integer.parseInt(data) - INDEX_OFFSET;
@@ -60,13 +60,21 @@ public void removeTransaction(String input, Account account) throws EmptyArgumen
         }
     }
 
-    // Checks whether the input index is an Integer
-    public static boolean isInteger(String data) {
+    public static boolean isNotInteger(String data) {
         try {
             Integer.parseInt(data);
-            return true;
+            return false;
         } catch (NumberFormatException e) {
+            return true;
+        }
+    }
+
+    public static boolean isNotDouble(String data) {
+        try {
+            Double.parseDouble(data);
             return false;
+        } catch (NumberFormatException e) {
+            return true;
         }
     }
   
diff --git a/src/main/java/budgetbuddy/transaction/type/Expense.java b/src/main/java/budgetbuddy/transaction/type/Expense.java
index 095e586565..8d8fa36583 100644
--- a/src/main/java/budgetbuddy/transaction/type/Expense.java
+++ b/src/main/java/budgetbuddy/transaction/type/Expense.java
@@ -7,6 +7,12 @@ public class Expense extends Transaction {
 
     public Expense(String description, double amount, String category, String date, Account account) {
         super(description, -amount, category, date);
+        assert this.getAmount() < 0: "Expense amount must be positive";
+        assert description != null && !description.isEmpty() : "Description cannot be null or empty";
+        assert category != null && !category.isEmpty() : "Category cannot be null or empty";
+        assert date != null : "Date cannot be null";
+        assert account != null : "Account cannot be null";
+
         account.setBalance(account.getBalance() + this.getAmount());
     }
 
diff --git a/src/main/java/budgetbuddy/transaction/type/Income.java b/src/main/java/budgetbuddy/transaction/type/Income.java
index d705394dd7..684dcb271f 100644
--- a/src/main/java/budgetbuddy/transaction/type/Income.java
+++ b/src/main/java/budgetbuddy/transaction/type/Income.java
@@ -7,6 +7,12 @@ public class Income extends Transaction {
 
     public Income(String description, double amount, String category, String date, Account account) {
         super(description, amount, category, date);
+        assert this.getAmount() > 0: "Income amount must be positive";
+        assert description != null && !description.isEmpty() : "Description cannot be null or empty";
+        assert category != null && !category.isEmpty() : "Category cannot be null or empty";
+        assert date != null : "Date cannot be null";
+        assert account != null : "Account cannot be null";
+
         account.setBalance(account.getBalance() + this.getAmount());
     }
 
diff --git a/text-ui-test/EXPECTED.TXT b/text-ui-test/EXPECTED.TXT
index 471c6f5580..61619e10e3 100644
--- a/text-ui-test/EXPECTED.TXT
+++ b/text-ui-test/EXPECTED.TXT
@@ -1,7 +1,6 @@
 Hello from
 BUDGET BUDDY
-What is your name?
-Hello James Gosling
+What can I do for you?
 ----------------------------------------------------------------------------------------------------------------------------------------
     Bye... Don't forget to keep track of your future transactions
 ----------------------------------------------------------------------------------------------------------------------------------------
diff --git a/text-ui-test/input.txt b/text-ui-test/input.txt
index 1329553ca2..b023018cab 100644
--- a/text-ui-test/input.txt
+++ b/text-ui-test/input.txt
@@ -1,2 +1 @@
-James Gosling
-bye
\ No newline at end of file
+bye