What If My Spouse and I Have Been Over Our HSA Family Limit? (Excess Contribution to an HSA)

You will have to notify the bank. The excess contribution will need to be reported with your 1040 filing on Form 5329. If you discover it after filing for the year, the amount can be penalized by 6% to 10% for each year it goes un-taxed. In this case, if you already filed for that year, you would have to file a 1040X amended return for that year along with a Form 5329. If you have several years, you'll have to file several amended returns.


SOURCES:
https://www.irs.gov/forms-pubs/about-form-5329

https://www.irs.gov/instructions/i8889