Over-paid taxes due to incorrect, under-stated deprecation for many years

[ZWu1]

Basically my CPA made a simple math mistake, for 9 years, by understating my depreciation on 2 townhouses I rented out, one already converted to self-use last year.

So I overpaid a large sum of taxes. Recently he found the issue.

1. The CPA said I won't be able to adjust/correct all previous years' cumulative over-paid taxes in 2024, due to a cap or limit. Instead, I will have to adjust the cumulative amount over many future years (by filing 3115 each year). Is this right?

2.  Since I converted 1 of the 2 townhouses to self-use, I am no longer to able to do any adjustment/correction for that townhouse. That is, my over-paid taxes is forever lost. Is this right?

Confused person who really appreciate any help! 

[rjs]

Duplicate question. Please keep all your related questions in one thread. Do not post separate questions about the same issue. When information is scattered in multiple threads it's confusing and hard to follow, and hard to see the whole picture. If you want to add more information or post a follow-up question, add a reply to your original question.