Emergency calls only. No data

[Sneary]

I have got no data and emergency calls only.

[pgn]

Has your phone been topped-up in the last 30 days, @Sneary? Guide How to Top Up (PAYG) 

If you have credit balance, check you have coverage Guide: Is the network down for me or everyone? 

Otherwise try removing and reseating the SIM card - give it a gentle wipe with a lint-free cloth to ensure the contacts are clean. While you have the SIM out, check it is an O2-branded SIM - if not, head into an O2 Shop today, with valid photo id, and let them replace the SIM for you - a free service, and they will ensure any balance and your number are activated on the new SIM. Good luck, @Sneary.

[MI5]

@Sneary 

Have you topped up or made a chargeable call in the last 6 months?

If not, you will be disconnected as O2 assume it to be a dormant sim.

7. Our Rights to Bar or Disconnect Your Mobile Phone

• 7.1. If you do not carry out any chargeable activity at least once in any 6 month period your Mobile Phone will be disconnected and you will lose any remaining credits balance on your Account. If you wish to be re-connected after this time you will be given a new Mobile Phone number.

• 7.2. We may at our discretion bar or disconnect your Mobile Phone if we have reasonable cause to suspect fraudulent use of a credit card/debit card, your SIM Card or Mobile Phone.

• 7.3. In addition to anything else we can do, we may bar or disconnect your Mobile Phone at any time if:

https://www.o2.co.uk/termsandconditions/mobile/on-pay-and-go-our-service-terms-are-worth-a-read