Mobile phone companies must cut international roaming tariffs for calls between European countries by up to 70 per cent today to meet EU regulations.

The deadline was set by a law passed by Brussels earlier this month, following a lengthy investigation by the European Commission into mobile operators' pricing structures.

The changes cap the roaming charges that operators can charge by introducing a maximum 'Eurotariff' for calls made and received within the EU of 49 and 24 Euro cents per minute respectively.

Without Brussels' involvement, tourists and businesspeople were paying up to four times higher more for EU mobile calls than their domestic equivalent.