How to Switch Carriers and Keep Your Number: The 10-Minute Port

The port is a 10-minute ritual — if you preflight it first

This guide is built from the FCC's published porting rules, each carrier's own transfer-PIN documentation, and manufacturer/carrier compatibility tools rather than first-hand use. Every figure below is dated so you can re-check it before you start.

Most people who dread switching carriers aren't afraid of the new carrier — they're afraid of losing their number. That fear is reasonable, but it's solvable with sequence. Do the prep in the right order and the actual port is a 10-minute ritual: gather three pieces of information, hand them to the new carrier, and wait for a text.

The part that wrecks people is doing it backwards — cancelling the old line before the new one has finished pulling the number over. We'll flag that danger clearly below, because it's the one mistake that isn't fixable.

Step 1 — Preflight: unlock status, coverage, and eSIM vs. physical SIM

Before you touch a transfer PIN, confirm three things.

Is your phone actually unlocked? Dial *#06# to pull up your IMEI, then check your current carrier's account settings or a carrier-run compatibility/IMEI checker for lock status. On an iPhone, go to Settings > General > About and look for "No SIM restrictions," which generally indicates the phone is unlocked. If your device is still locked, most carriers unlock eligible phones automatically 60 days after purchase or activation, and you can also call and request an unlock if you've paid it off and it's in good standing.

Will the new carrier's network actually work at your address? Every carrier-branded plan and most MVNO plans run on one of the big three networks underneath — that's the "rides T-Mobile's network" or "rides AT&T's network" language you'll see on MVNO pages. Check the new carrier's own BYOD/IMEI compatibility checker (each of the big three publishes one) and cross-reference the FCC's national broadband coverage map for your specific address before committing, since carrier-published coverage claims are self-reported.

eSIM or physical SIM? If your phone supports eSIM (most phones since roughly 2022, plus iPhone 14 and later in the US, ship eSIM-only), the new carrier can usually activate it remotely with a QR code the moment the port finishes — no waiting on a mailed card. If you're keeping a physical SIM, order it a few days ahead so it's in hand when you start the port.

Step 2 — Gather the three things a port actually needs

A number port needs exactly three pieces of information from your old carrier:

1. The number-transfer PIN (sometimes called a port-out PIN) — a one-time code your current carrier generates specifically to authorize the move.
2. The account number with your old carrier.
3. The billing ZIP code on the account.

Also write down the exact account-holder name as it appears on the old carrier's bill — first, middle initial, suffix, all of it. A name mismatch between what you type into the new carrier's port request and what's on file with the old carrier is the single most common reason a port gets rejected on the first attempt. If the account is in a spouse's or parent's name, use that name, not yours.

Step 3 — Where to get the transfer PIN (verified this month)

Carriers are required to make this self-service, and all three of the majors now put it in-app.

• AT&T: Open the myAT&T app, tap More > Manage Profile > People & Permissions, scroll to "Transfer phone number," and tap "Request a new PIN" — the six-digit code displays immediately. You can also dial *PORT (*7678) from the AT&T phone to get a text with a link to generate one. AT&T's standard consumer transfer PIN expires 4 days (96 hours) after you generate it, so pull it right before you start the port, not days in advance.
• Verizon: In the My Verizon app, tap Account > Edit profile & settings > Number Transfer PIN > Generate PIN. Dialing #PORT from the Verizon phone works too, and it texts you a link. Verizon's transfer PIN is good for 7 days.
• T-Mobile: In the T-Mobile app, go to Account > Profile Settings > Line Settings > "Request a transfer PIN." The dial-code equivalent is #PORT# (#7678#) from the T-Mobile phone. Only the primary account holder can generate a T-Mobile port-out PIN.

If the app or dial code fails, every major carrier's customer service line and retail stores can issue the PIN too — it just takes longer than the self-service path.

Step 4 — Start the port with the NEW carrier, never by cancelling the old one

This is the safety-critical step: you start a port by giving the new carrier your transfer PIN, account number, and billing ZIP — you do not call the old carrier to cancel anything first. Per the FCC's published porting guidance (checked September 2026), a phone number that's been cancelled or fully deactivated is released back into the numbering pool and is generally not recoverable. The port process is what moves the number; cancellation just deletes it.

Sign up for service with the new carrier (through their app, website, or in a store), enter the three port details plus the account-holder name exactly as it appears on the old bill, and confirm you want to "bring your number." The new carrier files the port request; your old service stays live the entire time, which is exactly what you want.

One honest note worth knowing before you start: per FCC guidance, a carrier cannot refuse to release your number over an unpaid balance or an unexpired contract — you can still owe that money afterward (they'll bill you), but they're not allowed to hold your number hostage to collect it. Porting itself is free; you're not charged a transfer fee by either side for the number move itself.

Step 5 — What happens in the window between "start" and "flip"

For a simple wireless-to-wireless port — one line, no complications — FCC rules require carriers to complete it within one business day. That one-business-day standard comes from the FCC's 2009 Local Number Portability order (FCC 09-41) and its 2010 implementation order (FCC 10-85), which took effect for major carriers in August 2010 — it isn't a new rule, it's been the baseline for well over a decade, and it's still the standard the FCC cites in its current porting guidance (checked September 2026). In practice, most single-line wireless ports finish in as little as 1-2 hours. Landline-to-wireless or wireless-to-VoIP ports can take longer, up to several business days, because more switching equipment is involved.

You'll know the port completed when your old SIM or eSIM suddenly loses signal — that's the number moving over, not a problem. If you're on eSIM with the new carrier, you'll typically get an activation text or app prompt to scan a QR code once the port clears.

If the port fails, the rejection almost always maps to one of the three details: a typo in the account number, a billing ZIP that doesn't match what's on the old bill, or — the most common cause — the account-holder name not matching exactly. Log back into the new carrier's port-status page, correct the mismatched field using what's actually printed on your old bill, and resubmit; a corrected resubmission usually clears within the same porting window.

Step 6 — After the port: the cleanup checklist

The number moving is not the finish line. Four things to confirm in the days after:

• The old account actually closed. A completed port does not always auto-close the old account in the old carrier's billing system — check your old carrier's app or call to confirm the account shows closed, not just "number ported, line suspended."
• Watch for a final prorated bill. Most carriers send one last statement covering the partial billing cycle up to the port date. That's normal; a full extra month is not — dispute it if you see one.
• Check for a device balance. If you financed a phone through the old carrier, porting the number does not cancel that installment plan — you still owe the remaining device payments even after you've left, typically billed as a final invoice or ongoing charges depending on the carrier's process.
• Re-verify your two-factor codes land on the new line. Banking apps, email, and other 2FA-linked accounts sometimes cache your old carrier's SMS gateway behavior. Send yourself a test code from your bank or email provider in the first day after the switch to confirm texts are landing.

A word on MVNOs, since a lot of switches land there

If the plan you're switching to is a low-cost MVNO running on someone else's towers, know the trade-off going in: MVNO traffic is deprioritized relative to the host network's own postpaid customers. In plain terms, on a congested tower — rush hour downtown, a stadium, a festival — the host carrier's own postpaid subscribers get network priority, and MVNO traffic is what yields and slows down first. That's true of Tello riding T-Mobile's network and it's true of most budget plans built the same way; it's not a bug specific to one carrier, it's how every MVNO agreement works. For most day-to-day use, off-peak, it's a non-issue; if you live or work somewhere towers get crowded at peak hours, it's worth knowing before you commit to an MVNO line.

Switching anyway? The plans worth popping in

If you're doing this whole ritual anyway, it's worth comparing what you're switching to, not just confirming you can keep your number. Tello currently lists Unlimited talk, text, and data for about $19/mo for your first 6 months, then $25/mo standard (checked September 2026) — check current price before you commit, since promo windows shift. If you'd rather stay inside the big three but want a straightforward postpaid line, check price at AT&T is worth a look too. For the full lineup ranked by what you actually get for the money, browse our current plan shortlist.

If you're comparing low-data options specifically, see how Tello stacks up against Mint Mobile on a low-data plan. Switching on a student budget has its own math — see the best cheap phone plans for college students. And if you just want a sense of what a solid MVNO line runs across the board, here's what a cheap MVNO plan actually costs in 2026.

FAQ

Will I lose service during the port? Your old line typically keeps working right up until the moment the port finalizes, then it cuts over to the new carrier — for a simple single-line wireless port that's often 1-2 hours, with the FCC's outer limit at one business day. You should not have an extended gap.

Can my old carrier block the port because I owe them money? No. Per FCC guidance, an unpaid balance or an unexpired contract is not a valid reason to refuse a port. You can still be billed for what you owe afterward, but the carrier can't withhold your number to force payment.

What's the single biggest reason a port fails? A mismatch between the account-holder name you enter with the new carrier and the name on file with the old carrier — more common than a wrong PIN or account number. Copy the name exactly as it appears on your old bill, including middle initials and suffixes.

Do I need a new SIM card, or can I use eSIM? If your phone supports eSIM — most phones from the last few years, and all US iPhone 14 and later — the new carrier can usually activate it instantly by QR code once the port completes. If you need a physical SIM, order it ahead of time so it's on hand before you start.

Is porting my number free? Yes — carriers aren't permitted to charge a separate fee for moving your existing number. You'll pay whatever the new plan itself costs, but the port isn't a billable add-on.