O2 has announced an overhaul of its tariff structures, including for Apple's iPhone in the UK.

Research by O2 suggested that half of mobile phone users find tariff structures and offers confusing, and the new deals are designed to be simple and straightforward.

The move follows recent reports that Apple's iconic iPhone failed to meet sales targets in the UK by around 10,000 units.

Unlike other O2 mobile phone deals, iPhone customers have been restricted to three tariffs (£35, £45 or £55 a month for 18 months) as well as an upfront fee of £269.

As part of the new structure, the three iPhone tariffs will be brought inline with the per-minute and text bundles offered with other deals.

Customers on a £35 per month contract will get three times more minutes and more than double the number of texts than before.

The new £45 iPhone tariff gives the same amount of minutes and texts as the former £55 tariff, so customers on the £55 tariff can either save £10 per month or take the new £75 tariff with a huge 3,000 minutes and 500 texts a month.

However, new iPhone customers will still have to pay the one-off £269 fee when they sign up.

Unlimited data browsing and access to The Cloud's Wi-Fi hotspots will continue to be included in all the iPhone packages.

Existing iPhone customers will be transferred to the new tariffs during February, and all customers will be moved by mid-March.

"This industry is infamous for confusing consumers with the number and complexity of tariffs," said Sally Cowdry, marketing director at O2 UK.

"We have listened to our customers and are offering simple but competitive tariffs across our handset range."

O2 has also launched a £1 per day flat-rate tariff for mobile web browsing on all new pay-monthly contracts for non-iPhone customers.

The new offer is aimed at occasional data users and will help to prevent accidentally running up large data bills.

The £1 rate is the maximum customers will pay if they browse more than 20-25 pages in a day. Below this, they will pay 4p to 5p per page.

More regular data users can opt for the Unlimited Web Bolt On at £7.50 per month which O2 introduced when it launched the iPhone.

The new tariffs will be available from 1 February 2008.