Help with your sim card

Find out how to top up and how to contact your network here

How to top up your sim card

So you've got your new sim card - hopefully from our choice of free Pay As You Go sim cards from 9 UK networks - and you now need to add some credit to the sim card. This is known as "activating your sim" or "topping up your sim".  

First of all, check the activation date for your sim card. For O2, Vodafone and Lebara sim cards you'll find the activation date on the white barcode label on the back of the sim card pack. You must top up your sim card before the date shown.

All other network sims should be activated, or topped up, within 30 days of the date of your order.

Place the sim in your phone and check that you have a signal from the network before you top up the sim card. You can also check this by ringing the mobile number shown on the barcode label - this is your new mobile number. O2, Vodafone, EE and Lebara sim cards give you your new mobile number on the white label on the pack.

For all other networks follow the registration details provided in the pack. You may not get a signal for those other networks until you have activated the sim by registering it on the network website. This is when the network will give you your new mobile number. 

See our network help guide below. 

Activate your sim within 30 days

We recommend that you activate your new sim card within 30 days of purchase, as not all networks show a final activation date. If you are not able to activate your sim card, within 30 days of purchase, for example if it has expired, just let us know and we'll send you a replacement. Always include your order number when contacting us, which you can do by using the link at the foot of this page. 

Keep your existing mobile number

If you wish to keep your current number and move it to your new sim card, you are entitled to do this regardless of which network you are on - it does not have to be the same network.

Follow our guide here:

How to keep and transfer your current mobile number

If you prefer you can use the new number the network give to you. Always remember that sim cards remain the property of the network and must be used in accordance with their terms and conditions of use. Their terms of use apply in all cases.

However, you have a right to retain your mobile number but do be aware that if your sim card is not used to make paid calls or texts for several weeks the network may disconnect your sim and you will lose your number, so we recommend that you familiarise yourself with their terms which you will find on the network's website.

You can also CHOOSE YOUR OWN GOLD NUMBER from our lists of thousands of UK mobile numbers, and can swap any of these numbers for your current one, even if you're on a different network. Your network and tariff will remain the same (unless you want to change it), the only thing that will change is your number. 

Use your airtime credit

If you are on a Pay As You Go tariff, do be aware that any credit you have on the sim card cannot be transferred or refunded and you will lose it when you transfer your number. We therefore advise that you first use up as much of your remaining credit as you can before you ask for your code. In most cases your credit will be automatically exchanged for an allowance or "plan", which will usually give you an amount of minutes, texts and data which lasts for 30 days. In this case there will be no credit to transfer anyway. This is also known as airtime credit or calling credit. 

How to top up your sim card

For all UK networks you can top up in the following ways:

1. By buying a top up voucher, which you can get from your local supermarket, filling station and stores such as newsagents and general grocery stores. You add the credit by phoning the network's helpline number and giving them the activation code on the top up voucher. 

2. By phoning the network's helpline number (see list below), where you will be able to pay by credit or debit card. 

3. By following the instructions on an ATM (hole-in-the-wall cash machine). This service may not be available for all networks or at all ATM cash machines. 

4. Most networks also let you top up by credit or debit card on their website and in their high Street stores.

5. Most networks also let you set up a direct debit payment from which they will take the monthly payment for your tariff every 30 days. Most Pay As You Go plans now operate a 30-day tariff which requires a set payment for a package of calls, texts and mobile internet data. 

Useful numbers - Activate and top up your sim card


Activate, top up and registration information

Website: EE UK website

Top up: Phone 150 from an EE sim or 07593 966 150 from any other phone


Activate: GiffGaff UK Activation


Activate sim: Dial 5588

Register: Lebara Register Sim


Top Up: Dial 321 or 92# from a LycaMobile sim or dial 07404000321 from any other phone

Top Up Online: LycaMobile top Up

Helpline: 322 from a LycaMobile sim or 0207 132 0322 from any other phone


Website: O2 UK Website

Top Up: Dial 4444 from your O2 sim or 0344 809 0222 from any other phone. 

Top Up Online: O2 Online Topup

Register your sim: O2 Register Sim 


Register and Activate sim: Smarty Activate Sim


Top Up: Dial 444 from your Three sim or 07782 333 444 from any other phone

Top Up Online: Three Online Top Up


Top Up: Dial 2345 from your Vodafone sim

Top Up Online (includes PayPal): Vodafone Online top Up

Activate Voucher Online: Redeem Top Up Voucher Online


Activate Sim and Register: Voxi Activate and Register Online

Voxi Online Chat: Voxi Contact Us

You can also use Vodafone facilities to top up your Voxi sim card



Your first two sim cards are completely free - Up to £1.98p is automatically deducted at checkout when you use the discount code FREESIM. No card details are required unless you are purchasing more than 2 sims or any other items, and this offer includes free UK postage.

Additional sims are available at 99p each but MUST be bought in the same transaction - we can only supply two free sim cards and can not accept repeat orders for free sims.