Both husband and wife filed as MFS, can we amend and change it to MFJ?

[chunhuach]

For some reason my ex-wife is not cooperating, so she filed as MFS.

we were divorced on Jan/2024, if we file as MFJ we will save about $20k to $30k.

I know mostly likely her tax will have issues (she ignored certain income and rely on my to report it but I will not), when I file my tax I will point these out (point out the right income split, we are in WA so income has to be spitted) in a form,  IRS will mostly go after her if they find out she's not reporting her share of income.

If she get audited, or contacted by IRS,  can we change to file as MFJ?

I looked online it says:

"Married taxpayers who previously filed as Married Filing Separate (MFS), Single, or Head of Household (HOH) may file a married filing joint return within three years from the due date of the original return without regard to extensions, provided the IRS did not mail either spouse a notice of deficiency for which a petition was filed timely in the U.S. Tax Court"

My hope is that somehow IRS will contact her so that and she can start to seriously consider it, and so we can amend the tax to file MFJ. But I worry if IRS directly send her a Notice of Deficiency then it's too late. I am not sure how IRS will work in this regard.

I know you will say why not talk with your wife? it's complicated, she's not coorporating, I offer to pay advisor fee so we can see a CPA together she refused. I know she will start to coorporate when she see she has a 20K tax liability.

[VolvoGirl]

Here's how to Amend MFS to Joint if you want to......
https://ttlc.intuit.com/turbotax-support/en-us/help-article/amend-tax-return/amend-married-filing-se...

[Opus 17]

You may amend MFS to MFJ, but both spouses must agree.

Also, you say your wife has "issues".  You should know that by filing a joint return, each spouse is jointly and severally liable for all income, deductions, facts, errors, omissions or other problems with a joint tax return.  If a problem is discovered, the IRS can come after either one of you, or both, or only you, if you have more money or are more easily collected from, even if the error is entirely your spouse's fault.  Filing a joint return ties your finances together forever, at least for the year you file (2023, in this case).   However, with separate returns, you are not responsible for errors or omissions on your spouse's return, even if they are intentional.  Depending on what the "problems" are, it might be wiser to pay the extra tax and keep your returns separate.