Answer: If you have a good history with this account — you always pay on time and you’re not carrying a large balance — adding him as an authorized user may help his scores.

The key is whether the credit card issuer will “export” this data from your credit file to his. Some issuers automatically do this export for any authorized user; others do so only for spouses. The only way to know for sure is to ask your credit card company.

If the data is exported to his file, it will be used to calculate his FICO scores, which are the scores most lenders use. The company that creates the FICO briefly toyed with the idea of excluding authorized user data in its latest formula, FICO 08, but ultimately decided to continue using it.

If you add him as an authorized user, you don’t need to give him a card or access to your account. What you should do, however, is take some time to go over his credit reports and discuss what steps he’s taking on his own to clean up his financial act.

A temporary boost in his scores might land you a mortgage, but you could wind up much worse off financially if he continues to mishandle his credit.

Answer: Not every lender uses FICO 08. When a new version of the FICO formula is rolled out, some lenders adopt it immediately while others may take month or years, or may never do so at all.

The bureaus only started offering FICO 08 to lenders this year, so it’s rather likely that many lenders will still be using the older versions to calculate your scores.