Your billing address doesn't match the country or region that's
Re: Your billing address doesn't match the country or region that's
Welcome to AdWords Community.
Google offers country specific promotional codes. According to what you have referred in your question, you are applying a code that does not apply to the country you have entered in your billing address.
For instance, if you billing address is USA, you will need to use a coupon code that is specific for USA only.
Where did you get this code from?
Country specific guidelines can be found here https://support.google.com/adwordspolicy/answer/1396257?hl=en