TalkTalk's new unlimited SIM is the cheapest in the UK

TalkTalk's new unlimited SIM deal is the cheapest in the UK

Unlimited minutes, texts and data, it's the holy grail of phone contracts - and usually a rather pricey one - but not if you're a TalkTalk customer.

The broadband and TV provider has launched its new All-in SIM giving its customers unlimited everything for just £12 a month, on a 30 day rolling contract.

That's a fantastic sounding offer - but there are a few caveats. First up, it's not a 4G deal, so you'll have to make do with 3G data speeds. Tethering is also not supported, so you won't be able to tie your handset to a tablet or laptop and let them feed off your phone's internet.

Plus you have to be a TalkTalk broadband or TV customer to take advantage of the deal, you can't just pick up the All-in SIM with no other attachments to the company.

Still great value

TalkTalk promises 99% UK network coverage, as it currently uses Vodafone's network to deliver services to users, so you shouldn't struggle to find signal (unless you're in a Voda black spot).

If you're not fussed about 4G speeds then TalkTalk's All-in SIM is a great deal, as long as you don't mind signing up to another one of its services if you're not already a customer.