diff --git a/src/main/java/dev/unlegitdqrk/unlegitlibrary/bank/CardBrand.java b/src/main/java/dev/unlegitdqrk/unlegitlibrary/bank/CardBrand.java
new file mode 100644
index 0000000..33540c9
--- /dev/null
+++ b/src/main/java/dev/unlegitdqrk/unlegitlibrary/bank/CardBrand.java
@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2025 UnlegitDqrk - All Rights Reserved
+ *
+ * You are unauthorized to remove this copyright.
+ * You have to give Credits to the Author in your project and link this GitHub site: https://github.com/UnlegitDqrk
+ * See LICENSE-File if exists
+ */
+
+package dev.unlegitdqrk.unlegitlibrary.bank;
+
+public class CardBrand {
+    public static final CardBrand VISA = new CardBrand(16, new String[]{"4"});
+    public static final CardBrand AMERICANEXPRESS = new CardBrand(15, new String[]{"34","37"});
+    public static final CardBrand MASTERCARD = new CardBrand(16, new String[] {
+            "51","52","53","54","55",
+            "2221","2222","2223","2720"
+    });
+
+    private final int length;
+    private final String[] prefixes;
+
+    public CardBrand(int length, String[] prefixes) {
+        this.length = length;
+        this.prefixes = prefixes;
+    }
+
+    public int getLength() {
+        return length;
+    }
+
+    public String[] getPrefixes() {
+        return prefixes;
+    }
+}
diff --git a/src/main/java/dev/unlegitdqrk/unlegitlibrary/bank/CreditCard.java b/src/main/java/dev/unlegitdqrk/unlegitlibrary/bank/CreditCard.java
new file mode 100644
index 0000000..f06d01e
--- /dev/null
+++ b/src/main/java/dev/unlegitdqrk/unlegitlibrary/bank/CreditCard.java
@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) 2025 UnlegitDqrk - All Rights Reserved
+ *
+ * You are unauthorized to remove this copyright.
+ * You have to give Credits to the Author in your project and link this GitHub site: https://github.com/UnlegitDqrk
+ * See LICENSE-File if exists
+ */
+
+package dev.unlegitdqrk.unlegitlibrary.bank;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Random;
+
+public class CreditCard {
+
+    private final String cardNumber;
+    private final CardBrand cardBrand;
+    private final Random random;
+
+    public CardBrand getCardBrand() {
+        return cardBrand;
+    }
+
+    public Random getRandom() {
+        return random;
+    }
+
+    public String getCardNumber() {
+        return cardNumber;
+    }
+
+    public CreditCard(CardBrand cardBrand) {
+        this.cardBrand = cardBrand;
+        this.random = new Random();
+        this.cardNumber = generateCardNumber();
+    }
+
+    public CreditCard(CardBrand cardBrand, int seed) {
+        this.cardBrand = cardBrand;
+        this.random = new Random(seed);
+        this.cardNumber = generateCardNumber();
+    }
+
+    private String generateCardNumber() {
+        int totalLength = cardBrand.getLength();
+
+        List<Integer> digits = new ArrayList<>(totalLength);
+
+        String chosenPrefix = null;
+        if (cardBrand.getPrefixes() != null && cardBrand.getPrefixes().length > 0) {
+            String[] prefixes = cardBrand.getPrefixes();
+            chosenPrefix = prefixes[random.nextInt(prefixes.length)];
+            for (char c : chosenPrefix.toCharArray()) {
+                digits.add(c - '0');
+            }
+        } else digits.add(1 + random.nextInt(9));
+
+        while (digits.size() < totalLength - 1) digits.add(random.nextInt(10));
+
+        int checkDigit = computeLuhnCheckDigit(digits, totalLength);
+        digits.add(checkDigit);
+
+        StringBuilder sb = new StringBuilder();
+        for (int i = 0; i < digits.size(); i++) {
+            sb.append(digits.get(i));
+            if ((i + 1) % 4 == 0 && i != digits.size() - 1) sb.append(' ');
+        }
+
+        return sb.toString();
+    }
+
+    private int computeLuhnCheckDigit(List<Integer> digitsWithoutCheck, int totalLength) {
+        int sum = 0;
+        int n = digitsWithoutCheck.size() + 1;
+
+        for (int i = 0; i < digitsWithoutCheck.size(); i++) {
+            int digit = digitsWithoutCheck.get(i);
+            int posFromRight = n - i;
+            boolean shouldDouble = (posFromRight % 2 == 0);
+            if (shouldDouble) {
+                int d = digit * 2;
+                if (d > 9) d -= 9;
+                sum += d;
+            } else sum += digit;
+        }
+
+        int mod = sum % 10;
+        return (10 - mod) % 10;
+    }
+}
diff --git a/src/main/java/dev/unlegitdqrk/unlegitlibrary/window/Window.java b/src/main/java/dev/unlegitdqrk/unlegitlibrary/window/Window.java
deleted file mode 100644
index 2ebf138..0000000
--- a/src/main/java/dev/unlegitdqrk/unlegitlibrary/window/Window.java
+++ /dev/null
@@ -1,17 +0,0 @@
-/*
- * Copyright (C) 2025 UnlegitDqrk - All Rights Reserved
- *
- * You are unauthorized to remove this copyright.
- * You have to give Credits to the Author in your project and link this GitHub site: https://github.com/UnlegitDqrk
- * See LICENSE-File if exists
- */
-
-package dev.unlegitdqrk.unlegitlibrary.window;
-
-public class Window {
-    WinUser.WNDCLASSEX wndClass = new WinUser.WNDCLASSEX();
-
-    public Window(String tile, int x, int y, int width, int height) {
-WinUs
-    }
-}