U.S. Income Reporting & Tax Identity Collection FAQ – Amazon

If you have received an email from Amazon stating that your Form W-8 is expiring or has expired, you must complete an updated Tax Interview to continue selling. To access the Tax Interview, see instructions here. If you are a non-U.S. person, failure to maintain a current Form W-8 will result in suspension of your selling privileges.

https://sellercentral.amazon.com/gp/help/external/200663290?language=en-US