Carrier unlocking is not one U.S. rule with three logos. The useful differences are how long you must wait, whether the carrier unlocks automatically, and how much stricter prepaid devices are than postpaid ones.
Quick conclusion
- Want the clearest published postpaid rule: T-Mobile still states 40 days of use on the line, plus full payoff and good standing.
- Need AT&T unlock: expect to submit the request yourself through AT&T’s unlock portal.
- Need Verizon: re-check Verizon’s official page right before you buy because Verizon has changed its policy and separates postpaid payoff rules from longer prepaid timing.
- Buying prepaid or MVNO-branded phones is usually stricter: the cheapest handset is often the hardest one to unlock quickly.
- If you switch often, factory-unlocked is the easiest answer.
Comparison criteria
Rules were checked on 2026-08-09 against carrier and industry pages. The comparison focuses on postpaid timing, prepaid timing, whether a request is required, and whether military or other exceptions are published.
Comparison table
| Brand | Postpaid rule to verify | Prepaid rule to verify | Published exception | Main watch-out |
|---|---|---|---|---|
| Verizon | Official policy page should be checked for current payoff-based rule | Current policy page lists a much longer prepaid timing standard | Military exception is published | Verizon has changed its unlock rules more than once |
| AT&T | Device must meet AT&T’s eligibility rules and be requested through the portal | AT&T Prepaid requires a longer service history | Military exception is available | AT&T does not treat every eligible device as auto-unlocked |
| T-Mobile | 40 days on network, fully paid, account in good standing | 365 days or sufficient refill activity for prepaid | Deployed military exception is published | Device financing and account status both matter |
| MVNO or prepaid brands | Follow the selling brand’s own unlock page | Often stricter than postpaid | Varies by brand | Same network is not the same thing as unlocked |
Carrier notes
Verizon
Verizon is the page to verify closest to purchase time. Its official policy page now distinguishes postpaid payoff conditions from a longer prepaid waiting rule, so older blog summaries can be wrong.
AT&T
AT&T’s portal remains central to the process. Even when a phone seems eligible, you should verify the account is clear, the device is paid off, and the request is submitted correctly.
T-Mobile
T-Mobile publishes one of the clearest postpaid standards: 40 days of activity on the requesting line, full payoff if financed, and good account standing. Prepaid rules are materially stricter.
MVNO and prepaid brands
An MVNO phone should be judged by the brand that sold it, not just the underlying network. A device sold on a T-Mobile-based or Verizon-based budget brand is not automatically portable to every carrier on that same network family.
Recommendations by scenario
You want to switch carriers soon
Buy an unlocked phone from the manufacturer if possible. That removes the main lock risk.
You already financed a postpaid phone
Check payoff status first. Most unlock delays happen because the installment balance, lost-device flag, or account standing is not fully resolved.
You bought a cheap prepaid handset
Assume the unlock timeline is longer than a comparable postpaid phone until the official page proves otherwise.
Limitations and FAQ
- A lock is different from compatibility. Even an unlocked phone still needs the right bands, eSIM support, and IMEI eligibility.
- Lost, stolen, or fraud-flagged devices do not unlock normally.
- Military exceptions are real but specific. Follow the carrier’s documentation instructions.
- FCC and CTIA pages set expectations, not instant unlock rights. The actual workflow still lives on the carrier’s own page.
Sources and update date
Checked on 2026-08-09 against Verizon, AT&T, T-Mobile, FCC, and CTIA pages.