Previously the minimum £35 contract offered an inclusive 200 minutes and 200 texts, this has now risen to 600 and 500 respectively.

The higher priced tariffs also receive a boost...

The £35 and £45 tariffs see a healthy increase in inclusive minutes and texts, while the old £55 tariff disappears completely with existing customers moved to the new £45 one.

A new higher priced £75 a month tariff rounds off the changes.

New customers can get these new tariffs from 1st February, although existing customers may have to wait until mid march for their tariffs to be brought in line.

As an existing iPhone customer, we are really pleased to tell you that we are upgrading your existing iPhone tariff during February and you will benefit by mid March at the latest.

You will receive a text message from us by 7th February 2008.

• Existing £35 iPhone customers

  We will be automatically upgrading you to the new £35 iPhone tariff which offers you 600 anytime minutes and 500 anytime texts a month. You will also continue to receive unlimited* UK data. All of this will be done for you without you having to do a thing and we'll text you to let you know when it's been done. Thank you for being an O2 customer.

• Existing £45 iPhone customers

  We will be automatically upgrading you to the new £45 iPhone tariff which offers you 1,200 anytime minutes and 500 anytime texts a month. You will also continue to receive unlimited* UK data. All of this will be done for you without you having to do a thing and we'll text you to let you know when it's been done. Thank you for being an O2 customer.

• Existing £55 iPhone customers

  We will be reducing the price of your 1,200 anytime minute iPhone tariff from £55 to £45. You will continue to get 500 anytime texts and unlimited* UK data at this new price. All of this will be done for you without you having to do a thing and we'll text you to let you know when it's been done. Thank you for being an O2 customer.

More details are available at the O2 site