Nearly a quarter of a million people who registered to be blood donors in 2022 have still not given.
Only about 91,000 of the 325,000 people who registered and received an appointment, according to exclusive data provided to BBC 5Live by NHS Blood and Transplant.
Due to low blood supplies in 2022, the NHS stated that new donors would have fewer appointments as existing donors would be given priority.
I've been explaining to people why it's so critical that they make appointments right away at the biggest blood processing facility in the UK, which is located close to Bristol.
The NHS Blood and Transplant Centre employee Phil Brown, who has spent 35 years there, required "multiple" blood transfusions to treat his leukemia.
He stated, "I had leukemia twenty years ago, and I believe leukaemia and bone marrow cancer, and I received numerous red cell and platelet transfusions during my treatment.
Making sure all the products are processed correctly and are safe and therapeutically effective is one of the main motivations I have for working at the center. It's very crucial. ".
"The situation is challenging in the sense of trying to get more donors," said Mark Chambers, assistant director at the Filton facility.
"We faced a challenge in October when we received an amber alert because we had only two days' worth of blood on hand.
We are currently at about six and a half days, but we are aware that many donors have registered in an attempt to enter the building. ".
According to him, O negative and RO are the two types that are most in demand right now.
We require O negative blood because it is a universal blood type that can be given to all patients, he explained.
"For sickle cell, we need donors who are RO, which is typically found in donors of African descent. ".
The NHS stated in a statement that low blood supplies would make 2022 challenging for the service.
There are fewer appointments available for first-time donors during these times because existing donors are given priority because their blood types are known and they are more likely to complete a successful donation, according to the statement.
Since then, blood supplies have "stabilized," according to the statement, and more slots are now open for new donors. Those who have already registered are urged to book right away.
According to NHS Blood and Transplant's David Rose, director of donor experience, "We always need new people to join our amazing community of lifesaving blood donors and help meet the needs of patients today and in the future. "Please make 2023 the year you save lives if you're one of the 235,000 individuals who signed up last year but haven't yet attended a scheduled appointment or are considering signing up to donate.