Report via TMZ -- Tupac Shakur is the most famous person ever incarcerated at Clinton Correctional Facility in New York, but he still needed an I.D. when he was behind bars ... and now it can be yours -- for a few grand.
Pac's first prison I.D. card from his infamous 1995 incarceration is going up for auction through the memorabilia company, Heritage Auctions ... and they're starting the bidding at $2,000.
Tupac served 9 months behind bars after he was convicted on sexual assault charges ... and he was required to carry this laminated I.D. card at all times. Pac started his sentence on Valentine's Day, and 2 weeks later he was issued this prison I.D. -- which includes his signature.
While he was locked up, Tupac wrote a letter to his then-girlfriend and included some super graphic sex scenes ... and the NSFW artwork sold earlier this year at auction for $21,000.
You won't have to break the bank for his prison I.D. though ... the bidding starts July 1, and Heritage Auctions is expecting this piece of Pac history to fetch between $4,000 and $6,000.