To unblock your Nationwide debit card, the method depends on whether the card is by you, locked due to incorrect PIN entries, or blocked by Nationwide's fraud systems. 1. Unfreeze a Card via the App
If you cannot remember your PIN, you can request a PIN reminder via the Nationwide Internet Bank by going to "Other account services" > "Request a PIN reminder". A new PIN will be posted to you within 3–5 working days. Card is "Frozen" (Manually Blocked): how do i unblock my nationwide debit card
Here’s a clear text guide you can use or share: To unblock your Nationwide debit card, the method
Insert your card into any UK cash machine with the LINK sign. Enter your PIN and select PIN Services , then choose PIN Unlock . A new PIN will be posted to you within 3–5 working days
Choose "PIN unlock" . The screen will confirm the unlock was successful.
If Nationwide blocked the card because they detected suspicious activity, you cannot unblock it yourself via the app. You must speak to them to verify the transactions.