I have now tried for about 10 times over a two month period to change my credit card to continue with my subscription . Every time the system comes up with “there has been a glitch” and the support system is useless as I have had no help with this since October. I can’t work with a company that doesn’t care whether i am struggling to MAKE A PAYMENT. So, GOODBYE
My advice: use Paypal. You can link that to your credit card or bank account and it’s free, provided you use it once a year, and you have buyer protection.
I’ve been using it for years for international purchases. For renewing your Avast subscription it works perfectly, confirmation of renewal always within 1 minute.