I have a new client (retiree, filing jointly) who has been carrying over a $500 tax credit since 2014 in form 1116. Client does not have plans to open any business/investment overseas in the future.

Client only income is from retirement accounts (401k and Roth)

If no foreign income is generated in the future, when will the client be able to use the credit? by the client estate? is worth it for the client to keep track of the tax credit in form 1116?

(Note: client wants to stop filing 1116)

thanks.