How to cancel AT&T, Verizon, T-Mobile, or any wireless carrier — including dealing with early termination fees and device payment plans.
Log into your carrier account and look for: remaining device installment balance, early termination fee (ETF) if applicable, and contract end date. These are the main costs of switching.
Wait until after your billing cycle starts — you pay for the full month regardless. If you have a device installment plan, your final bill will include the remaining device balance.
If keeping your number, port it to your new carrier FIRST. Porting automatically cancels your old account. Do NOT cancel before porting — you'll lose your number.
Call the carrier's cancellation line (not general support). Say: 'I want to cancel my service.' They will transfer you to retention. Decline any offers if you're decided. Ask for cancellation confirmation number.
If you leased a device (common with newer iPhone plans), you must return it within 30 days or be charged full retail price. Get a return receipt from any carrier store.