Countingup doesn't send out your PIN in a letter. Instead, you can view your PIN in the app at any time.
Follow these steps to view your PIN:
1. Open the Countingup app
2. Go to the ‘Balance’ tab
3. Tap the ‘Card’ button at the top of the screen
4. Tap 'Get Pin'
5. Enter the 3-digit security number (CSV) shown on the back of your Countingup card