Freeserve will this week formally warn 700 of its heaviest users that if they don’t cut down on their use they will be disconnected.

The company is targeting subscribers to its unmetered service who are online for an average of more than 16 hours a day.

Freeserve’s decision is the latest in a catalogue of headaches facing ISPs when offering flat rate access.

Back in August AltaVista abandoned plans for its unmetered service before it had even launched.

In July Breathe.com was obliged to disconnect its heaviest flat rate users users.

Most recently World Online was forced to change its unmetered pricing structure because of the hefty costs of subsidising its flat rate user base.

However Freeserve claimed it was only targeting a minority who were “abusing the service.” It won’t affect the company’s overall commitment to providing a flat rate service.