A rare blood type whose red cells carry no A, B or H antigen. Because the H antigen is the foundation A and B are built on, none of the usual markers are present. Read the full explanation.

In India, roughly 1 in 10,000 people. Screening studies of blood donors have found rates as low as 0.005%. It is much more common in some communities than others. Sources and detail.

Red cells with the Bombay phenotype carry no A antigen, no B antigen and no H antigen. In principle that makes them compatible with any recipient, which is why the phenotype is sometimes described as a universal donor variant.

In practice it is far too scarce to be used that way. A unit of Bombay blood is one of very few things that can help a patient with the same phenotype, and nothing else will do for them. So it is kept for those patients rather than spent where ordinary blood would serve.

If you have the Bombay phenotype, the most useful thing you can do is be findable — which is what a register is for.

No. O-negative cells still carry the H antigen, and a patient with the Bombay phenotype has anti-H that attacks them. Only blood from another person with the same phenotype is safe.

Yes — it is inherited recessively, so siblings are the most likely match and testing close relatives is often the fastest route to a donor. More on inheritance.

When you complete a donor registration, your details and any certificate you upload are stored against your account. That is where it currently stops.

• Verification has not begun — no one is reviewing your certificate yet.
• There is no matching, so your record is not being searched against any patient.
• Nobody will be contacted about a donation on the strength of this record.

We will write to you when verification starts. In the meantime the most useful thing you can do is keep your availability accurate, so that when we do get in touch it is at a moment that suits you.

You can correct your details or withdraw from the register entirely, at any time, from your account.

Rarely. Only when a patient nearby needs your specific blood group, and only while you are marked available. Long silences are normal and are not a sign that anything has gone wrong.

Yes. Mark yourself unavailable from your account — travelling, unwell, or simply not right now. Your entry stays and you will not be contacted until you change it back.

No. You can say no to any individual request, for any reason, and it does not remove you from the register.

The donors on this register are volunteers giving something scarce. Confirmation by a treating doctor, blood bank or pathologist is what lets them trust that every request is real and clinically needed. It also means the people arranging a donation are qualified to judge what is actually required.

It depends on how many suitable donors are near you and whether they are available. Coordinators will tell you honestly where a search stands. If blood is needed urgently, your hospital and blood bank remain the route to use.

That is common and not a problem. Register and nominate them anyway — we will explain who we are when we contact them.

There is no public list of donors or patients on this site, and there is not going to be one. No page, and no data behind a page, exposes a donor or patient name, contact number, address or medical detail.

Inside the team: coordinators work from records that are masked by default — they see a reference, a status, a city and a blood group, and nothing that identifies you.

When someone does need your contact details in order to help, they have to ask for them explicitly. That request is recorded against their name, along with the time it happened, whether or not it was granted.

You can withdraw at any time. Withdrawing removes you from any future search.

Not through us. A coordinator sits between the two sides of every match and is the only person who sees both. Anything that does need to be shared is asked for first, specifically, and can be refused. See the Privacy Notice.

From your account, at any time. You will not be contacted again.

No. In a medical emergency, contact your hospital or blood bank directly, or call your local emergency number. We cannot arrange urgent transfusions.

No. We connect people. Collection and transfusion happen through the medical system, as they always would.

No. Registering as a donor or making a request through your doctor is free.