Hi there @Seller_Zk2qYQO7ZJB1G - and thank you for looking to the seller forums for some information on valid charge methods.

I can help share the following help page for instructions on updating your charge method information as well as this FAQ on why a charge method may be listed as invalid. On this topic, it states:

"Why is my credit or debit card listed as invalid?

We verify your credit or debit card based on the following requirements. Violating one or more of the requirements below will result in your card being denied by Amazon.

• The number that you entered must match the number on your credit or debit card.
• The billing address that you entered must match the billing address on your credit or debit card statement.
• The CVV code that you entered must match the code on your credit or debit card.
• The card expiry date must be at least six months from when you add the card.
• The card holder’s name that you entered must match the card holder’s name on your credit or debit card (in the Latin-script alphabet).
• The card must not be a prepaid, virtual or gift card.
• The card must be chargeable in the currency of the Amazon store or stores for which the card is being provided.
• The card must have adequate credit limit to pay for the charge.
• If you were asked to enter a unique security code by your financial institution, the code that you entered must match the code sent to the card holder via SMS, email or token.
• Multi-factor authentication must be completed. For existing cards, please re-add the card in Seller Central and complete the authentication challenge.

If your card meets all of the requirements above, but is still listed as invalid, we recommend that you try a different card or contact your financial institution for assistance. If you’ve tried at least two different credit or debit cards that meet the requirements above and all of them were denied, contact Selling Partner Support for assistance."

I can recommend doublechecking your information against that list, but if issues still continue please do connect with both your financial institution and Amazon Seller Support for more technical troubleshooting.

I hope this helps, and thanks again for posting!

-Danny