Switching to O2: everything you need to know
If you’ve decided to switch your phone provider to O2, this guide is here to help! We’ll cover what to check before you move, how to switch, and what to expect on the day your service changes over. You’ll see how to keep your number with a PAC, how a STAC works if you want a fresh start, and where people usually get caught out with costs or coverage.
What you’ll learn
- How to check O2 coverage in your local area
- Which O2 plan type fits different budgets and usage patterns
- When you need a PAC or a STAC (and how to get one)
- What usually happens on the day the switch happens
- The extra costs to watch for, including early exit fees and price rises
Step 1: Decide if O2 makes sense for you
Most smooth switches come down to two things: signal and cost. Get those right first.Check coverage in the places that matter
Use O2’s coverage checker with your full postcode. Don’t just check your home, you should include work, regular travel routes, and anywhere you rely on your phone day to day.Indoor signal can differ significantly from outdoor coverage, so it’s worth checking both.If you want a full walkthrough, see How to check O2 coverage.Check your phone and SIM setup
Make sure your phone supports 4G or 5G on O2 as some phones are locked to their current network provider. Then decide if you want a physical SIM or an eSIM.An eSIM can be easier if you don’t want to wait for a card or keep swapping SIM trays, but your phone will need to support eSIMs.Check your contract status with your current network provider
If you’re still in contract, switching early can trigger a cancellation fee. Ask your current network what you’d owe before you set a switch date so you’re not caught off guard later.Step 2: Choose the right O2 plan type
Your plan choice affects both your monthly bill and how locked-in you are.Pay Monthly vs Pay As You Go
| Plan type | Best for | Commitment | What it’s like |
| Pay Monthly SIM-only | You’re happy with your phone | 30 days, 12 or 24 months | Fixed bill, no handset cost |
| Pay Monthly with phone | You want a new handset | Fixed term | One contract, one bill |
| PAYG Rolling Plan | You want flexibility | No fixed term | Automatic payment, no top-ups |
| PAYG Big Bundle | You prefer manual top-ups | No fixed term | Top up, then swap credit for data |
Watch for price changes
Some O2 plans include annual airtime price rises, usually applied in April. Check the plan details so you know what the cost could look like a year or two down the line.Step 3: Understand what you get with O2
Before you switch, it helps to understand the value you’ll be gaining.Why people choose O2
- EU roaming is included on many plans (within data limits)
- O2 Priority perks are available, even on Pay As You Go
- eSIM support on compatible devices
Where O2 may fall short
- Indoor coverage can vary by postcode
- Airtime price rises can affect long-term value
- Some headline deals only work if you add extras
Step 4: Decide what happens to your number
This choice determines which code you need.PAC vs STAC
| PAC | You want to keep your number | Text PAC to 65075 |
| STAC | You want a new number | Text STAC to 75075 |
Step 5: Switch to O2
Keep your number (PAC switch)
- Order your O2 plan or SIM (physical or eSIM).
- Text PAC to 65075 from the number you want to keep.
- Enter the PAC in My O2 when prompted.
- Keep your old SIM active until the switch completes.
- When your old service drops, insert or activate your O2 SIM.
Get a new number (STAC switch)
- Text STAC to 75075 from the number you’re closing.
- Give the STAC to O2 in My O2.
- Start using your new O2 number once the old service ends.
What to expect on the day you switch to O2
A short service gap is pretty common.Your old network usually drops first. Once that happens, swap SIMs (or activate your eSIM), restart your phone and wait for signal to return. If you’re still without phone signal by the evening, it’s best to contact O2 customer service.Common problems and quick fixes
PAC or STAC text doesn’t work
Some accounts can’t use the text service. Therefore, try to request the code through your account or contact O2 customer support.Service still isn’t connecting
If your phone isn’t receiving signal follow these troubleshooting tips.- Restart your phone
- Check that the SIM is correctly in the device
- Turn airplane mode on and off
Frequently Asked Questions
Do I need a PAC to keep my phone number?
Yes. If you want to move to O2 and keep your current number, you’ll need a PAC from your existing network.
Do I need a STAC to get a new number?
Yes. A STAC tells your old network to close your number so you can start with a new one on O2.
Will I lose service during the switch?
Usually, yes but only briefly. Your old network typically drops first, then O2 connects once the switch is made.
Should I check O2 signal coverage before switching to O2?
Yes, definitely check phone coverage in your local area and inside your home and workplace. Coverage affects everyday use far more than plan features.
Who do I contact if I can’t switch to O2?
O2 Support can check switch status and fix issues quickly. Use the O2 customer service contact guide to reach the fastest option.
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