UK telecoms regulator Ofcom has published a new quarterly report that shows the most complained-about telephone and pay TV suppliers.

Complaints about mobile phone services are now being classified as ‘pay monthly’ and ‘pay as you go’ (pre-pay) customers. Ofcom says around 95% of mobile complaints come from users with ‘pay monthly’ contracts, with the number of ‘pay as you go’ complaints currently too low to be statistically valid.

UK telephone and broadband company TalkTalk has launched a new mobile phone service for its customers. These offers, which build on the company’s existing virtual network agreement with Vodafone UK, are only open to consumers who’ve chosen one of the company’s fixed-line services.

TalkTalk Mobile promises handsets that are completely free and tariffs that start from £5 a month.

Ofcom has published the fourth edition of its quarterly UK telecoms complaints data. The report covers the final three months of 2011.

As with previous periods, overall mobile complaint levels were much lower than for fixed-line telephones and fixed broadband services. For the Q4 2011 period, Ofcom received the fewest complaints about O2 and the most complaints about Orange.

Telecoms regulator Ofcom is warning consumers to check they aren’t owed money when they switch to a new communications provider. It estimates at least £10 million has been unclaimed in the past two years; that's around £5 for every customers who's switched to a different landline, mobile, broadband or pay TV provider.

Ofcom says mobile and fixed-line communications providers need to do more to publicise services for disabled customers. It's just published the results of mystery shopping research that looked at telephone-based and online help available from BT, Orange, O2, TalkTalk, T-Mobile, Three, Virgin Media and Vodafone.