The Proof of Income Letter is normally provided by an employer.
If your mother-n-law receive social security benefits - it is a benefit verification letter.
This letter is sometimes called a "budget letter," a "benefits letter," a "proof of income letter," or a "proof of award letter."
You cannot request a benefit verification letter online for another person - your mother-n-law must do that in person.
She can request a benefit verification letter online by using your my Social Security account.
To set up or use your account to get a benefit verification letter, go to Sign In Or Create An Account.
If you can’t or don’t want to use your online account, or you need a letter for someone other than yourself, you can call us at 1-***-***-**** (TTY 1-***-***-****), Monday through Friday from 7 a.m. to 7 p.m.
You may also visit a local SSA office. Let me know your zip code - and I will find the office serving your area.