Key Takeaways
- Never cancel your current service before the port is complete — doing so kills your number.
- You'll need your account number and PIN from your current carrier to begin the transfer.
- Most number ports complete within 24 hours, though some take up to three business days.
- Unlocked or compatible devices work immediately; locked phones may require an unlock request first.
- Your old service cancels automatically once the port is finished — no extra call needed.
What you will need
What Number Porting Actually Means
When you switch carriers and keep your existing phone number, the process is called a number port (short for Local Number Portability, or LNP). Federal law guarantees U.S. consumers the right to port their mobile number to any carrier — meaning you own your number, not the carrier. The new carrier handles most of the coordination; your job is to provide the right information and avoid a few common missteps.
If you're also weighing a switch on the home internet side, the same planning-first approach applies. See our guide to switching internet providers without losing service for a comparable walkthrough.
What you will need
What You'll Need Before You Start
Gather these items before contacting your new carrier. Missing any one of them is the most common reason ports stall.
Current carrier account number
Required by the new carrier to initiate the port request on your behalf.
Account PIN or transfer PIN
Authenticates the port request and prevents unauthorized number transfers.
Unlocked phone or compatible device
Ensures your handset can connect to the new carrier's network bands.
New SIM card or eSIM from new carrier
The physical or digital card that connects your device to the new carrier's network.
Backup of phone data
Protects your contacts, photos, and apps in case anything goes wrong during the transition.
If you're new to how carrier plans work — data types, contract terms, and what "unlimited" actually means — this ground-up overview of phone plans is a useful read before you commit to a new service.
Step-by-Step: How to Port Your Number
Follow the steps below in order. The sequence matters — particularly the instruction not to cancel your existing service early.
Retrieve your account number and PIN from your current carrier
Log into your current carrier's app or website, or check a recent bill. Look for your account number — not your phone number — and your account PIN or transfer PIN. Some carriers issue a separate number transfer PIN; call customer service if you can't locate it online.
Confirm your phone is unlocked
A locked phone is tied to one carrier and won't work on another network even with a new SIM. Check your phone's settings (on iOS: Settings > General > About; on Android: Settings > Connections > Mobile networks) or contact your current carrier. If it's locked, submit an unlock request before proceeding — carriers are legally required to unlock a fully paid-off device upon request, though processing can take a few days.
Sign up for a plan with your new carrier — but don't activate yet
Select and purchase a plan with the new carrier. During sign-up, you'll be asked whether you want a new number or to transfer an existing one — choose transfer existing number. Provide your account number, PIN, and the exact name and billing address on your current account. The new carrier uses this to submit the port request.
Keep your current service active until the port completes
Do not call your old carrier to cancel service, and do not pay off and close the account before the port finishes. An account that is closed or suspended cannot be ported from. Your old service will cancel automatically once the transfer is complete.
Insert the new SIM card or activate your eSIM
If you received a physical SIM, power off your phone, swap the SIM card, and power back on. For eSIM activation, follow the QR code or app-based instructions from your new carrier. The port typically completes within a few hours to one business day. During this window, you may briefly lose service — this is normal.
Verify the port and test your service
Once your new carrier confirms the port is complete, make a test call to a known number, send a text, and disable Wi-Fi to test mobile data. Check that your number displays correctly when calling out. If anything doesn't work within 24 hours of the confirmed completion, contact your new carrier's support line with your port confirmation details.
Never Cancel Your Old Service Early
Closing or suspending your account with your current carrier before the port finishes will permanently release your phone number. Once released, a number cannot be recovered — it re-enters the carrier's pool and may be reassigned. Keep your old account open and active until you receive confirmation from your new carrier that the port is complete.
After the Port: What to Expect and Check
Once the port completes, your old service cancels automatically and your new SIM or eSIM activates. Here's what to verify immediately:
- Calls and texts: Make a test call and send a text message to confirm both work.
- Data connectivity: Disable Wi-Fi and load a webpage to confirm your cellular data plan is active.
- Voicemail: Your voicemail box on the new carrier starts fresh. Set up your greeting and PIN right away so callers don't reach a generic or inactive box.
- Final bill: Expect one last bill from your old carrier covering any remaining balance or prorated days. Review it and keep a record.
If you're switching to a new device at the same time, our step-by-step guide to setting up a new smartphone without losing data walks you through transferring contacts, photos, and apps safely.
Port Timing Can Affect Your Bill
Most carriers bill in monthly cycles and don't prorate mid-cycle cancellations. Timing your port near the end of your current billing cycle can reduce the overlap you pay for. Check your current cycle end date before initiating the transfer.
Before signing any new service agreement, it's also worth reviewing what to look for in the contract. Our checklist at Before You Sign a Phone Contract covers early termination fees, device locks, and auto-pay terms.