Hi Gillian Nott
To update your credit card information for paying your Azure monthly invoice, please follow the steps below:
Sign in to the Azure portal as the Account Administrator.
In the search bar, type and select Cost Management + Billing.
Under My subscriptions, choose the subscription you'd like to update.
Select Payment methods from the menu.
Here, you can:
Add a new credit card by clicking the "+" icon and entering your new card details. You can also check the box to make it your active payment method.
Edit existing card details as needed.
https://learn.microsoft.com/en-us/azure/cost-management-billing/manage/account-admin-tasks#navigate-to-your-subscription%27s-payment-methods
https://learn.microsoft.com/en-us/azure/cost-management-billing/manage/change-credit-card
Please note that Azure currently only accepts credit or debit cards for payments—Electronic Funds Transfer (EFT) is not supported.
If you run into any issues during the update process, such as errors or declined payments, we recommend checking for any outstanding balances or contacting your financial institution.
Kindly let us know if the above helps or you need further assistance on this issue.
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