To qualify for these, you need to have been an O2 PAYG customer for six months or more. Three tariffs are available, £11, £16 and £21. All of them last three months; the first one comes with 100 minutes, 500 texts and 100MB data, the second one, 200 minutes, unlimited texts and 250MB data and the last one 300 minutes, unlimited texts and 500MB data.
Amongst the 20 or so plans on offer, the one that caught our eyes is the Nokia Lumia 520 available on the £11 plan. The phone by itself costs £110 (including a £10 top up) at Carphone Warehouse and this contract carries a total cost of ownership of £132.
As a reminder, the Nokia Lumia 520 comes with a dual-core Qualcomm Snapdragon processor clocked at 1GHz, 512MB of RAM, 8GB onboard storage a microSD card slot, a 5-megapixel rear camera (but no front facing one), HD video recording, a microUSB port, a 4in 800 x 480 pixel display, up to 15 hours talk time, GPS and Windows Phone 8.