Tell them to Double check their bank statements and Check IRS account (both accounts if married)
Your Online Account | Internal Revenue Service
The IRS shows they sent it to them. A lot of people forgot they got the deposit last March - May 2021. Or missed one payment and entered the wrong amount. Then when the IRS reduces their refund and they check their bank accounts they have been finding the payments.
If the IRS thinks they sent it to you but you didn't get it request a trace for a missing third Stimulus payment
https://www.irs.gov/newsroom/questions-and-answers-about-the-third-economic-impact-payment-topic-j-p...
