Your NBI reference number appears on the portal right after you book your slot and choose how to pay. If you closed that screen, log in at clearance.nbi.gov.ph...
Category - NBI
You can’t pay for an NBI clearance with PayPal directly. The NBI’s payment options are GCash, Maya, online banking, 7-Eleven and Bayad Center. The...
To pay for your NBI clearance through Bayad, choose Bayad Center as your payment option on clearance.nbi.gov.ph and note the reference number. Then pay in cash...