Yes, this is very normal and is something we've been seeing a bit more lately. Once it arrives, punch in the code in seller central and it will verify your address and you will be all set.
Another verification method Amazon has been doing is setting up video calls so they can identify their sellers more easily.
Why is Amazon sending me a postcard?
I think I meesed up, Amazon is making me wait for a postcard to validate me address.
Why is Amazon verifying my address?
