In the attached Contract description..
3. Overview
a. DHSC is planning to deploy negative Covid-19 test certification minimum viable
product, to enable workplaces, educational centres, health and social care services and places of business to open to members of the public who have tested negative for COVID-19 within a specified timeframe in addition to other criteria.

And how it will be used..
Sample use case:
1) Assisted Tests. Supervisor registers citizen by entering name, email address (optional), photo (from smartphone camera) and scans QR code on testing box to enter details including unique identifier of the test itself automatically. An audit trail is required to determine who assisted with the test. Citizen takes test, supervisor validates result and Negative COVID Test Status is issued, possibly as a QR code.

- Procedure to allow citizens to obtain evidence of their negative COVID test status
- Negative COVID Test Status Evidence is provided in form of a QR code that can be scanned and verified by other individuals/organisations
- Appropriate anti-Fraud measures"