Three to increase out-of-allowance costs - but you're unlikely to be able to leave penalty-free

Pay-monthly customers who use up all of their inclusive allowance will see the cost of calls to standard UK landlines and mobiles rise from 35p/min to 55p/min, while the cost of picture messages and international calls and texts is also going up.

To cut your mobile costs and see how you could pay as little as £5/mth, see our guide.

Who's affected by the price rise?

The following groups of customers are affected:

• Those on contract handset plans, who joined Three or upgraded on or after 14 March 2014.

• Those on contract Sim-only plans, who joined Three or upgraded on or after 15 July 2014.

• Those on contract mobile broadband plans, who joined Three or upgraded on or after 12 August 2015). 

Pay-as-you-go customers are not affected.

Which prices are going up?

Here's a full list of the changes which come into effect on 18 June.

• Calls if you go beyond your allowance are going up to 55p/min (from 35p/min). This applies if you’ve used up all your monthly inclusive allowance and make calls to standard UK landlines (starting 01, 02 or 03; excludes calls to the Isle of Man or the Channel Islands), UK mobiles (any network) and your Three voicemail (if you’re on one of our Essential Plans).

• Calls to numbers starting 084 and 087 are going up to 55p/min from 45p/min. Numbers started 118 and 09 are also affected.

• Multimedia messages are going up to 55p from 40p. This includes pictures and video messages.

• International calls to Europe from the UK are going up to £1.25 min (currently 46p-55p/min). This includes calls from the Isle of Man but not those from the Channel Islands.

• International calls to the rest of the world from the UK (including the Channel Islands) are going up to £1.75/min from 46p-£1.02/min.

• International texts from the UK are going up to 35p (from 25p).

Most WON'T be able to leave penalty-free

While Ofcom rules let you escape penalty-free if your monthly tariff's increased and you weren't warned at sign-up, sadly the same protection doesn't apply to out-of-allowance price increases, unless you can successfully claim you've suffered "material detriment" as a result.

Three says that for most customers the increase is unlikely to be a "materially detrimental change".

However a spokesperson said: "Regular users of outside-of-allowance calls who are likely to suffer material detriment as a result of the price increase will be given the right to leave without charge, in line with our terms and conditions. We expect that this will be less than 1,000 customers."