At least 30,000 people will be given home blood group test kits as the NHS tries to identify 5,000 people with critically O negative blood.
The first 6,000 kits will be sent out this week by NHS Blood and Transplant to people who have recently registered as blood donors but have not yet made a first appointment.
Those found to have O negative blood will be offered priority appointments to ensure they become long-term donors.
The NHS said it was the first-ever mass home blood group testing campaign in the UK.
The search will be expanded as needed and kits will be shipped to up to 100,000 people registered with Give Blood over the coming months until enough people with O-negative blood are identified and booked to donate.
It is the first time the method of using large-scale home test kits to identify people with a specific blood type and book them for priority appointments has been tried by the NHS.
The kit is a simple finger-prick test, with a few small drops of blood, a litmus test-style chart, and a table to match the results, which is all it takes to figure out a probable blood type in five minutes.
O-negative blood is particularly valuable because it is the “universal donor” type that can be given to almost anyone, making it especially valuable in emergencies when there is no time to test a patient’s blood type.
About 13% of hospital inquiries are of this type, but only 8% of the population has it.
David Rose, director of donor experience at NHS Blood and Transplant, said: “Patient needs and medical advances are changing and already certain blood types are needed more often than others.
“We need an ever-increasing proportion of our blood donors to be O negative to meet increasing hospital demand for this type.
“If we know your blood type and you are universal O negative, we can prioritize your first appointment to save up to three lives and help keep blood supplies resilient this winter.
“This innovative new home test kit could be the key to helping newly registered donors understand if they have the requested O negative blood type and that we want them to act and book their first appointment as soon as possible.”