What can I do if my mother's 30 year long employer didn't allow mom to do her taxes?

Something else that disappeared from my prior post. The employer is also not paying their share of the Social Security taxes.

Well, it's not uncommon for unethical employers to not correctly pay their employees as employees. What's in it for the employer is that they don't pay the employer's share of Federal Unemployment Tax ( which is what states use for their administrative costs of the state paid unemployment benefits). The employer also avoids state taxes for unemployment and coverage for on the job injuries. An individual may purchase Medicare Part A for a very healthy cost since it wasn't paid as she went through her working years. (Self employed people often mess themselves up by not reporting their income, or not all of it to not pay taxes. They end up cheating themselves out of all the Social Security they might have earned if they had reported correctly. But I digress.)
Of course there is way to cause this employer some pain. It might not work due to understaffing at IRS. It also might draw attention to mom as well. Turn the employer in to the IRS and claim a reward. It's hard to get but if you turn them in and back taxes are collected you can get a 10% reward. Turn them in to the state agencies as well. If the situation is big enough and flagrant enough it could turn into a criminal prosecution and a big tax bill for that employer. That might give you some satisfaction.
Signed, Vegaslady, retired IRS Revenue Officer, (AKA Tax Collector).

If Mom was paid under the table for 30 years she is not entitled to SS or Medicare. Besides income taxes federal and State, Social Security had to be deducted and matched by the employer. No SS no medicare. The only way she could possibly get around this is if she is married or had been married for at least 10 yrs or more. Than she can collect off her husbands/ex's work history. But, she may need to say she has never worked.

Your Mom should have insisted she wanted a W2 form to do taxes. Her employer was wrong in not providing one and should have been reported. It now can't be corrected. As said, he could not keep her from filing taxes.

Sorry, it looks like you may have to support Mom when she can't work. She maybe able to collect Medicaid?

JoRogen, on another post, you mentioned your Mom got paid under the table. This is strange that an employer would be doing that for 30 years. Having proof of paying employees [be it a W-2 or 1099] the employer can deduct that on their own business income taxes.

Perhaps I'm missing something but I don't understand how an employer, or anyone, could prevent someone from preparing her own taxes.  Did the employer refuse to give her 1099s?   Was your mother an actual employee or an independent contractor?

Seems to me that if someone interfered with someone else's obligation to pay taxes, that first person might be guilty of some type of tax interference and violation of federal tax laws.  VegasLady is a poster who could address this better.  Hopefully she'll see this thread and respond.

It was your moms responsibility to file her taxes. It is illegal to get paid under the table and not report the income. No one can not let you file your personal tax returns.

So not contributing to the system may just have serious consequences for her and her family.