What is an NTN and do I need one?

Quick answer

An NTN (National Tax Number) is your tax identity with the FBR. For individuals it's your CNIC number; companies and AOPs get a separate number. You need an NTN to file tax returns, open a business bank account, issue proper invoices, claim sales-tax input, and appear on the Active Taxpayer List — so practically every formal business needs one.