The IT agency wants two thirds of practices across at least two existing PCT areas to take part. They will have summary patient records uploaded to a central database - the NHS spine - from late this year.
The pilot's success will be evaluated independently by a group of academics.
Joint GP clinical lead for Connecting for Health, Professor Mike Pringle, said: 'There are some areas where there is critical mass, and where there are pockets of hosted systems, such as Bradford and Gateshead, and London would be attractive.
'We need to choose an area where we are confident that data quality will be high.'
The summary records will be available to support clinicians treating patients in settings including A&E and walk-in centres.
In response to pressure from GPs, less information will be uploaded automatically to the summary records than originally proposed in guidance last year.
Summary records will include details of allergies and adverse reactions, as well as current and regular medication.
Details of major procedures or major diagnoses will not be included as planned, unless patients give specific consent.
GPs using IT systems supported by Connecting for Health will be able to mark data in their patient records that should be included in the summary, allowing the record to be expanded as patients allow.
Professor Pringle said: 'I think Connecting for Health has acted responsibly in reacting to GPs' concerns but also trying to maintain the best possible system.'
Practices will not be allowed to take part in the pilot unless their patient records meet accreditation standards that are set by Connecting for Health. The standard will be similar to that of the IT directed enhanced service.
Professor Pringle's fellow GP clinical lead Dr Gillian Braunold said the pilot would assess whether access controls to the summary records were workable, and how successfully information was loaded on to the spine.
Professor Pringle added: 'We will look at patients' views and doctors' views, and assess whether it makes a difference to patient care.'
He said if the pilot indicated that summary records needed to contain more information to be of use to clinicians in other parts of the NHS, they would 'think again' about how to achieve this.
SUMMARY RECORD LIMITED
- Adverse reactions, allergies
- Current and regular prescriptions
- Major diagnoses
- Major procedures