My husband and I have a married filing jointly filing status. Forgot to switch it.

We've been separated (not legally) for 16 months. Have different addresses. Well I did my return as married filing separately cause I didn't want him to have access to my funds this year.

Well he went to file his, and said he's getting charged but he also makes like 100k a year so I think it has to do more of what he makes than me filing separately. What do you think?