Resale properties don't come with the same fresh paperwork as a new launch, so a bit of extra diligence goes a long way before you commit.
Start with the title chain: ask the seller for the original allotment letter or sale deed, and every sale deed in between if the property has changed hands more than once. A property lawyer can run an encumbrance check to confirm there's no pending loan, litigation, or lien against the unit.
Confirm outstanding dues directly with the resident welfare association or builder — maintenance charges, any special assessments, and electricity/water bills should be cleared or accounted for in the final settlement. Ask for the latest maintenance receipt and a no-dues certificate where the society provides one.
For apartments, check whether any structural changes were made without society approval, and whether the unit's actual carpet area matches what's mentioned in the original sale deed. For independent floors, verify that construction was done as per the sanctioned building plan, since unauthorised additions can complicate a future resale or bank loan for the next buyer.
Finally, if the original project was RERA-registered, the registration doesn't automatically transfer any protection to a resale buyer in the same way it does for the first buyer — but it's still worth checking the project's RERA page for any recorded complaints or issues before you finalise the deal.