O2 Classic Pay As You Go is our simplest ever tariff. Calls are 3p a minute, texts are 2p each, and each MB of data is just 1p. Just top up a minimum of £10 and pay for what you use. Your credit won't expire, and once it runs out you can just top up again.You'll also get lots of perks, just for being on O2. You'll get free treats on Priority, up to 10% back on your top-ups every 3 months, and free access to 1000s of O2 Wifi hotspots across the UK.This sim pack includes instructions on how to top up. As soon as you've topped up, your sim will be ready to use.