Mobile broadband contracts could come with an automatic €50 limit to stop users getting a nasty surprise in their bill.
Communications regulator Ofcom claims roaming outside Europe and in the UK are the biggest cause of unexpectedly high mobile phone bills.
Ofcom has asked UK operators to introduce automatic usage caps and warnings for all mobile broadband use – but the regulator could force them to be provided.
Ofcom said: “As many as 1.4 million mobile phone contract customers may have been affected by ‘bill shock’ in the past six months.”
“Ofcom will now work with the mobile industry on a series of measures to address the main issues identified by the review.
“If these do not sufficiently reduce consumer harm, Ofcom may consider mandatory options to tackle the problem.”
European Union regulators have already forced mobile operators to automatically warn and cap data usage for EU citizens roaming inside the EU.
They will vote in April on whether to extend the same protection to EU citizens travelling anywhere in the world with an EU-based mobile operators.
But Ofcom said it will ask UK-based mobile operators to offer all customers the option to set a limit on their data usage both outside the EU and inside the UK.
It wants operators to make data tariffs easier to find on their websites and publicity material.
The regulator is also going to research the potential for automatically capping data usage unless users opt-out.
There’s also new Ofcom advice for consumers on how to avoid unexpectedly high phone and broadband bills, and what to do about them.