Two social security number

Just wanna get some advise from you guys. So my dad has two different social security numbers under the same name. How do I tackle this issue? Is this a big problem? He recently got his green card through my petition. Thanks a lot.

the older one was never used for anything. hes been using the newer one for the last decade for everything.

I would say get a advise from a lawyer.

That is quite odd and shocking. It sounds like one of those is fake and then he got the original one. I fee like once he files his tax return with the original one that will be it. That's what happened with most of us when we got SSNs. Once we filed our tax returns and mailed letters to the credit bureaus letting them know that we have SSNs now, the ITiNs became history.

both of them are real, that he had applied under his name.

How and why did he get two?

He shouldn't have applied for a new SSN when he got his green card, are the names identical? IMO you need professional advice.

Why two?

seeing how something shady had been done in the past, talk to a lawyer before making a mistake that you'll regret.