From July on, European mobile phone companies must cut off customers after their monthly data-roaming tab reaches €50, unless they explicitly agree to extra charges.

And the maximum price one phone company can charge another for downloading or uploading data will drop from €1 to €0.80 per megabyte.

Just in time for the summer, the caps should help holidaymakers avoid unwittingly racking up huge bills for web-browsing, e-mailing and using other mobile apps in another EU country.

The new caps follow the introduction in March of an EU rule allowing customers to opt for a maximum monthly tab (€50 by default) for data-roaming. Providers have to warn customers when they are close to reaching their limit and get their permission to raise it.

In another break for customers, the maximum price for making a call from abroad will drop from €0.43 to €0.39 a minute in July. Mobile users will also benefit from a lower cap on charges for calls received - €0.15 instead of the current €0.19.

And operators will no longer be allowed to charge customers for receiving a voice mail while abroad in the EU.

All prices exclude VAT.

The EU capped cross-border mobile calls in 2007 after finding they were on average four times more expensive than domestic calls. Since then, prices for calls abroad have dropped 70% compared with 2005 prices. The caps were extended last year to include text messages and mobile data services.

Earlier in June, four leading telecom companies lost their bid to overturn the caps. The European Court of Justice upheld the price limits in the interest of protecting consumers and improving the internal market.