DoH guidance dating from 2006 requires PCTs to provide practices with data on areas including elective activity and referral rates.
Practices use this data to decide on which services to spend their practice-based commissioning (PBC) budgets.
But practices in North Somerset said that they were receiving no data until late last winter. One practice manager said that her colleagues have been 'tearing their hair out'.
The difficulties stem from problems with Cerner Millennium, the IT system used at Weston General Hospital.
As a result, North Somerset PCT received very poor data to pass on to practices. The practice manager said the problems had made it impossible to implement PBC.
Weston Area Health NHS Trust said that the computer problems have now been fixed.
A DoH survey last week revealed that the majority of practices have still never commissioned a service.