In short
Raise a billing problem in writing before the carrier's dispute deadline (60 days at T-Mobile, 180 days at AT&T), and keep paying the undisputed part. Retention ("loyalty") teams can offer a better plan, but leaving has costs: device installment balances usually become due and you pay for the whole bill cycle. If the carrier does not fix the problem, an FCC informal complaint gets a written answer, usually within 30 days. No major carrier asks for your PIN, password or one-time code in a call or text it starts; turn on the free number-lock features to stop SIM-swap and port-out fraud.
How complaints work in this industry
- The FCC reviews each complaint and in many cases serves it on the provider, which has up to 30 days to respond to you and the FCC. Not every complaint is served; some are only shared internally or referred to another agency. FCC Consumer Help Center
- The FCC asks you to try the provider first. An informal complaint costs nothing and you do not need to appear in person. FCC: filing an informal complaint
- If the carrier's answer does not satisfy you, you may file a formal complaint within 6 months of the carrier's response (or of its due date if it did not respond); otherwise the informal proceeding closes. 47 CFR 1.718
- The FCC does not resolve individual complaints about unwanted calls or texts (including robocalls); those complaints feed enforcement and policy work. FCC Consumer Help Center
- The big three carriers require a written Notice of Dispute before arbitration and give themselves 60 days to resolve it: AT&T (then small claims or JAMS arbitration), Verizon (then AAA arbitration or small claims) and T-Mobile (then AAA arbitration or small claims). AT&T Verizon T-Mobile Terms
- Bill dispute deadlines differ: T-Mobile requires written notice within 60 days after you first receive the disputed bill or charge; AT&T allows 180 days from the bill date. T-Mobile Terms AT&T Consumer Service Agreement
- Many state utility commissions do not handle wireless complaints. Missouri's PSC says it does not regulate cellphones or internet providers. Missouri PSC
- New York's Department of Public Service sends cellular telephone complaints to the NYS Attorney General. NY DPS
- North Carolina's Public Staff sends wireless complaints to the NC Attorney General's Office. NC Public Staff
- Ohio's PUCO does not regulate wireless rates and refers wireless billing problems to the Ohio Attorney General; Oklahoma's Corporation Commission says non-lifeline wireless is regulated by the FCC. PUCO Oklahoma Corporation Commission
Your leverage
- Carriers point cancelling customers to retention offers. AT&T's cancellation page invites you to talk to a loyalty expert at 800.331.0500. AT&T
- Verizon tells customers to call Customer Service before disconnecting to see if they qualify for additional offers. Verizon
- T-Mobile's cancel page asks you to call so it can review the account and see what options it can offer to keep you. T-Mobile
- Price changes can open an exit. Verizon lets you cancel an affected line within 60 days of the notice with no early termination fee if a change has a material adverse effect on you and Verizon does not negate it after you object. Verizon Customer Agreement
- T-Mobile gives at least 14 days' notice of a change with a material adverse effect. Under Last Month Price Lock and the Un-contract Promise, if T-Mobile raises the price and you tell it within 60 days that you are leaving, it covers your final month's recurring charges. T-Mobile Terms T-Mobile price lock FAQ
- Outage credits depend on the carrier. Verizon credits postpay customers who lose service in their coverage area for more than 24 hours in a row when Verizon is at fault, if they call within 180 days. Verizon Customer Agreement
- AT&T says a qualifying network interruption gets an automatic credit for a full day of service under the AT&T Guarantee. AT&T
- T-Mobile's Terms state no outage credit and say T-Mobile does not promise uninterrupted service. T-Mobile Terms
- Free account locks block number theft. Verizon's Number Lock prevents port-outs and SIM Protection blocks transactions that need a new SIM; both are free. Verizon Number Lock Verizon SIM Protection
- AT&T's Wireless Account Lock blocks a number transfer; T-Mobile's Port Out Protection can be removed only by the Primary Account Holder; Cricket's Account Lock prevents SIM swaps and port-outs while it is on. AT&T T-Mobile Cricket
- On November 15, 2023 the FCC adopted rules that require wireless providers to use secure methods to authenticate a customer before moving a number to a new device or provider, and to notify customers immediately of a SIM change or port-out request. FCC news release
Traps
- Cancelling a line usually makes the device balance due at once. AT&T: the remaining installment balance is due immediately and you pay for the entire bill period. AT&T
- Verizon: any remaining device payment balance is due in full on the final bill, and cancellation takes effect on the last day of the billing period. Verizon
- T-Mobile: porting out deactivates service immediately, but you are charged for a full billing cycle, and cancelling may accelerate equipment installment or lease payments. T-Mobile Terms
- "Price lock" offers exclude a lot. T-Mobile's 5-Year Price Guarantee fixes the monthly price for talk, text and 5G data; it excludes taxes and fees, per-use charges, add-ons, third-party services and network management practices. T-Mobile price lock FAQ
- T-Mobile's Terms say surcharges may change without notice regardless of any price-related promotion, subject to its 14-day notice policy for material adverse changes. T-Mobile Terms
- Accepting a credit to settle a T-Mobile bill dispute fully and finally resolves the issue under its Terms. T-Mobile Terms
- Device returns cost money and have short windows: Verizon 30 days with a $50 restocking fee; AT&T 14 days with up to $55 at a store; T-Mobile 14 days in store or 20 days after shipping, with a $25 to $75 restocking fee. Verizon AT&T T-Mobile
- Trade-in and upgrade returns have deadlines. AT&T charges the remaining installment balance if the original device is not sent back within 30 days. AT&T
- Home internet gateways from wireless carriers carry large non-return fees: T-Mobile up to $370 if not returned within 14 days of cancelling; Verizon up to $300 per unit if not returned within 30 days. T-Mobile Verizon Customer Agreement
- Number Transfer PINs expire: 4 days at AT&T, 7 days at Verizon and 14 days at Google Fi. Do not cancel the old line before the port completes. AT&T Verizon Google Fi
- Prepaid balances are usually lost. T-Mobile prepaid service is non-refundable; Straight Talk deactivates service and forfeits unused days when the number ports out. T-Mobile Terms Straight Talk terms
- Arbitration deadlines are short: T-Mobile's Terms require an arbitration or court proceeding within two years of the date the claim arises, where the law allows. T-Mobile Terms
Scams to watch for
- Fake "fraud department" calls and texts ask for a PIN or one-time code so the scammer can sign in as you. AT&T says it won't contact you and ask for a PIN or code, or ask you to read back a passcode used to sign in. AT&T
- Verizon says it will never contact you to request any password, PIN, Social Security number or payment information. Verizon
- T-Mobile says it will never send a request for sensitive personal or account information, and tells customers not to confirm such data in response to an unsolicited email, text or inbound call. T-Mobile
- SIM swap: a scammer convinces the carrier to move your service to their phone. Port-out fraud: a scammer opens an account at another carrier and moves your number there. FCC news release
- The FCC says data breaches can raise the risk of these scams by exposing information that makes it easier to steal a phone account. FCC news release
- Discount or shutoff calls that demand gift cards, prepaid cards, crypto or a money transfer. AT&T says it won't contact you and ask for a prepaid or gift card for payment. AT&T
- Cricket describes callers posing as Cricket who offer discounts for prepaying by prepaid or gift card. Cricket
- "Return your device" scams: a caller claims a defect, recall or security alert and asks you to ship your phone. AT&T says it won't ask you to ship your phone to an unknown address. AT&T
- Report scam texts by forwarding them to 7726 (SPAM); AT&T, Verizon and T-Mobile all accept this, and forwarding is free. AT&T Verizon T-Mobile
- If your number was moved without permission, Verizon says to dial *611 from a mobile phone or call 1-800-922-0204; Cricket says to call 1-800-274-2538. Verizon Cricket
By the numbers
- ACSI 2026 (surveys April 2025 to March 2026): wireless phone service scored 77 out of 100, a record high. Among national carriers, T-Mobile scored 78 and Verizon and AT&T 76 each. ACSI study
- ACSI 2026: value MVNOs scored 79 (Consumer Cellular 84, Straight Talk 80, Mint Mobile 79, Google Fi 75) and full-service MVNOs 77 (Spectrum Mobile and Metro by T-Mobile 78, Xfinity Mobile and Cricket 76, Boost Mobile 74). ACSI study
- ACSI 2026: call center satisfaction was the lowest-rated benchmark for the national carriers, at 75 (72 in 2025). ACSI study
- FCC data-security settlements: T-Mobile agreed on September 30, 2024 to a $15.75 million civil penalty plus a $15.75 million cybersecurity investment over breaches investigated from 2021, 2022 and 2023; AT&T agreed on September 17, 2024 to a $13 million settlement over a January 2023 vendor breach. FCC: T-Mobile FCC: AT&T