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How to Top Up (PAYG)

Level 94: Supreme
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Updated by @Cleoriff 01/02/2023


*** There are various ways to Top up a PAYG mobile, if the the FIRST top up fails for any reason you can use a voucher to complete the top up. These are available from any O2 shop or other shops displaying a green top up logo.


This Top Up guide covers these PAYG Tariffs:


* Classic tariff (NOT available for NEW customers)

* Big Bundles HERE 

* Rolling Plans. HERE 


Keeping your SIM connected


If you don’t top up, add a Bolt On or carry out any chargeable activity at least once in any six month period, your O2 Pay As You Go sim card will be disconnected and you’ll lose any remaining credit on your account. More here (Updated by @Dave-O2 on 18 Jan 2024)


Checking your balance/allowances


Call 4444 free, then choose option 2 and 2 again.


Text BALANCE free to 20202.


Visit My O2.




* Via My O2 App or online

You are able to top up your phone via the app.

* This includes Android, Windows and iPhones (with iOS9 and above)

The App can be downloaded from Google Play or iTunes


*O2 Top-Up line

If you're in a direct dial country, you can call the O2 Top-Up line for free by:

  • Calling 4444
  • Using Hotkey 3 on your Pay & Go mobile
  • Calling +441753 552 277 from any phone
  • Calling 03456 062 277 from any landline

If you're topping up from a country that doesn't allow direct dialling, enter *111*# then press the call button. Your mobile will go on standby for a few seconds before it rings.

Answer the call and follow the instructions to access the Top-Up line by dialling 4444#.


Top up using debit or credit card

This is a very easy way to top up and very handy when abroad.

  • You must register the card with O2 first.
  • Dial 4444 and choose option to top up via card. You will be asked if you wish to register a card
  • You will be asked for the name on the card, the long number, the expiry date, the security code
  • Once this is done and accepted, you will then be able to top up. (A maximum of £100 over 30days)

Subsequent top ups (using the same card)

* Dial 4444 and choose option to top up via card.

* You will be asked the following questions:

* The mobile number you wish to top up

* The last 4 digits of the card, the security code, the expiry date and the amount you wish to top up

* Once complete you will be informed 'Your top up has been successful'

Important info: This method will allow the card holder to top up any mobile on the O2 network (even if the card holder is on contract) Important to stress the card must be registered with O2 PAYG service first.

Only cards registered in the UK can be used to top up.

  • MasterCard Maestro (including pre-paid versions)
  • Visa
  • Visa Delta
  • Visa Electron

NB at the time of editing, NO virtual cards from digital banks ie Monza, Revolut, Skrill etc can be used to top up.


 *E-Top Up cards (If you still have one you can continue to use it although they have been phased out from O2 stores.

If you have an E-Top Up card, simply:

  • Call 248 free from your mobile
  • Enter the 19-digit number on the back of the card
  • Enter the 5-digit PIN under the scratch panel on the back of the card

You'll then get a text confirming that the card has been registered successfully and the credit will be added to your account.

Once you've activated an E-Top Up card, you can use the card to top up your mobile anywhere you see the E-Top Up logo.


*Auto Top-Up

To get started, sign in to your My O2 account and activate auto top-up.

You can then set a regular day or date to top up your mobile, with a specific amount of money. You can even set top-ups to activate when you're low on credit. We'll take care of the rest and you can cancel at any time.


*Other ways to top up

  • Buy a voucher from an O2 shop.
  • Buy a voucher in any other shop where you see the green top-up logo.

Please note the voucher will expire after 12 months


*Topping up abroad


If you're off on holiday, it's a good idea to top up your mobile before you leave. But if you need to top up overseas, you can:

  • Take an O2 voucher with you
  • Call the O2 Top-Up line and use your credit/debit card (Which needs to be registered to your account)
  • Top up online (we recommend using wifi to avoid data charges)

*Top-up limits

  • The maximum amount you can top up your mobile with your credit/debit card is £100 every 30 days
  • There's also a £30 limit per 24 hours. If you've already topped up to this level with a credit/debit card, you'll need to use one of our other methods, like E-Top Up or vouchers
  • If you add credit using vouchers, or in your local shop using E-Top Up, you can top up a maximum of £50 at once
  • You can add credit by voucher and E-Top Up as often as you like, and there's no limit to the amount you can top up in a given period of time

*Mobile top up alternative. (Helpful when abroad/struggling with UK based cards)

You can easily purchase O2 top up online via and top up your O2 mobile within 1 minute. You select the O2 top up amount, then you check the order and you pay the phone credit using one of the secure payment methods. After payment, you will receive the top up voucher code via email. You can then directly top up your O2 Pay as you Go Plan using the instructions given




NB: How to Pay your Mobile bill (Contract) see here