If your Mastercard^® has been lost or stolen, here are 2 ways to prevent any fraudulent transactions.

From your web browser:

1. Sign in to your online bank.
2. Click Overview in the main menu and select your credit card.
3. Click Lock or cancel my card.
4. Follow the instructions.

Watch our demo on how to lock, unlock or replace your credit card from your online bank.

From the National Bank app:

1. Sign in to the National Bank app.
2. Select the credit card you’d like to lock.
3. Click More, then select Lock or cancel my card.
4. Follow the instructions.

Watch our demo on how to lock, unlock or replace your credit card from the app.

If you lock your credit card, you’ll no longer be able to complete any transactions with it. You also won’t be able to use it if you request a replacement card.

Travelling outside the country?

Call us to check if we can replace your card while you’re outside the country:

• From the United States: 1-800-361-0070
• Anywhere else in the world: 514-844-8026. From a landline. We accept collect calls.
  

You can also contact Mastercard Global Service^® at the local number of the country you’re visiting. Your call will be redirected to our customer service department.