How to Activate a Lebara SIM in the UK

The short answer

Put the SIM in your smartphone and turn it on

Lebara's UK help page says a physical SIM activates when it is inserted into a smartphone and the phone is switched on.¹ Another official help page gives the same instruction and says you can then browse or buy a plan if you have not already done so.²

There is no activation form to hunt down for the ordinary smartphone route. Give the phone a minute or two to register on the network, then test a call, text or mobile-data connection.

If you still need a plan, check the current referral journey and make sure the expected offer appears before paying.

Thirty seconds of preparation

Before you open the SIM tray

• Keep the SIM packaging.It may show your new mobile number, and it is handy if support asks for SIM details.
• Connect to Wi-Fi.You can still open help pages or account details if mobile data needs attention.
• Charge the phone.A flat battery halfway through setup is not a network fault, however convincingly it sulks.
• Check the handset is unlocked.Lebara says a phone locked to its original network must be unlocked by that network.¹
• Do not discard your old SIM.Keep it until any number transfer is complete and calls are reaching the Lebara SIM.

Physical SIM setup

Activate it step by step

1. Turn the phone off.This is the least dramatic way to change a SIM.
2. Open the SIM tray.Use the phone's eject tool and note which way the old SIM sits.
3. Remove the right SIM size.Lebara's multi-size card lets you pop out the format your phone needs. Start large and only press out a smaller frame when required.
4. Place the SIM flat in the tray.Match the cut corner. If it needs force, stop and check the orientation.
5. Close the tray and switch on.Wait for the phone to show a network name or signal bars.
6. Turn off Wi-Fi for the data test.Open a simple web page, then make a call or send a text.

If the phone asks for a SIM PIN that you did not set, check the card or documents that came with the SIM rather than guessing repeatedly.

Prove it works

Run four small checks

Lebara says you can check your balance in MyLebara, by dialling *#1345# and pressing call, or by dialling 5588 and following the spoken instructions.¹

New SIM, new number

How to find your Lebara number

Dial *#100# and press the call button. Lebara says the number will appear on screen. It may also be printed on the back of the original SIM packaging.⁴

Save the number temporarily even if you plan to replace it with your old one. It makes support and porting checks less fiddly.

Keeping your existing number

Activate first, transfer second

Lebara's order is clear: activate the new Lebara SIM, text PAC to 65075 from the old network's SIM, then complete a port-in request for your chosen date.³

Do not test the new SIM by immediately binning the old one. Keep both labelled and available until incoming calls and texts to your familiar number arrive on Lebara.

No signal or no service?

Work through the likely causes in order

1. Restart once.It gives the phone another chance to register the SIM on the network.
2. Reseat the SIM.Switch off, remove the tray and check the SIM is flat and correctly aligned.
3. Check for a network lock.A locked handset may reject a SIM from another network.¹
4. Check the plan or credit.A working SIM without usable allowance can look suspiciously inactive.¹
5. Try another location.This helps distinguish an activation issue from weak local coverage.
6. Contact Lebara.If the phone still rejects the SIM or cannot register, use official support rather than repeatedly changing unrelated settings.

If calls work but mobile data does not, the SIM has probably activated. Treat that as a data-settings or coverage problem rather than starting the whole activation ritual again.

Do not leave it in the drawer

Lebara gives you 30 days from the order date

Lebara says the SIM must be activated within 30 days of the order date. Miss that window and you can no longer use the chosen plan or promotion.²

That makes early activation worthwhile even if the number transfer is planned for later. Check the plan and service while there is still time to sort out a delivery or SIM fault.

Open the current Lebara referral route if you have not ordered yet, and confirm the plan, discount and renewal price shown in checkout.

Quick answers

Lebara SIM activation questions