How can I find out my blood type in the UK?

Most people find out they don’t know their blood type at a strangely ordinary moment. A form asks for it. A relative mentions theirs. You start giving blood. Suddenly, "what blood type am I?" becomes a question you’d quite like answered.

And drawing a blank is normal. GPs don’t routinely check blood groups, so you can go through years of NHS appointments and blood tests without ever being told yours.

If A, B, AB, O and the Rhesus factor are unfamiliar territory, our guide to how blood groups work covers that side of the subject. Here, the question is simpler: where can you actually find your blood type in the UK?

How can I find out my blood type in the UK?

You have several options. You may already have a result in your medical records, you can find out after donating blood, or you can use a blood type test at home. The NHS may also test you when knowing your group has a medical purpose, including during pregnancy or before a transfusion.

The main routes are:

• Check: Look through existing NHS or hospital test results if you’ve previously had blood grouping done.
• Donate: Blood donation services test donated blood and can tell you your group.
• Test: A home blood group test can indicate your ABO and RhD type for personal information.
• Ask: If blood grouping is medically required, your healthcare team will arrange the appropriate laboratory test.

There isn’t a central UK database where everybody can enter their name or NHS number and retrieve a blood type.

Will the NHS tell me my blood type?

Not routinely. The NHS blood groups guidance says GPs do not normally check a person’s blood group simply so they know it.

That sometimes surprises people. You can have plenty of blood taken by the NHS without having a blood group test because different blood tests measure different things. A full blood count, for example, examines blood cells and related measurements. Blood grouping is a separate test.

NHS pathology services even use separate samples for full blood counts and group-and-antibody screening.

So asking your GP what’s my blood type? may produce the answer if it has already been recorded. It doesn’t mean they’ll order a new blood group test purely to satisfy curiosity.

Can I find my blood type in the NHS App?

Possibly, if you’ve previously had the right test, but don’t expect it to appear automatically.

NHS Blood Donation specifically notes that you cannot usually find your blood type from your NHS number or in the NHS App. At the same time, the app can show test results and documents that have been added to your GP health record. That means an older blood-group result may be visible if it was recorded and made available to you.

Places worth checking include:

• Test results: Look for previous blood grouping or group-and-antibody-screen results.
• Documents: Hospital or maternity letters may contain your blood group.
• Older records: Ask your GP surgery if the information predates what you can currently see online.

The NHS notes that some results from before October 2023 may not appear automatically in the app.

Will a normal blood test show my blood type?

Usually not. A blood type test has to be specifically performed.

A routine full blood count checks measures such as haemoglobin, red and white blood cells and platelets. A blood group test instead looks at how your red cells react with specific antibodies to establish your ABO and RhD group.

This distinction matters if you’re scanning an old set of results looking for A+, O- or something similar. If nobody ordered blood grouping, the answer probably isn’t hiding somewhere under another test name.

And blood type tells you nothing about markers such as iron stores, inflammation or cholesterol. Those require separate testing. If blood tests have come up because you’re feeling persistently drained, our persistent fatigue guide explains the different causes worth considering.

Can I find out my blood type by donating blood?

Yes. Donating blood is one of the clearest ways to receive a professionally determined blood group if you’re eligible to donate.

Every donation is tested for blood group as part of the blood service’s laboratory process. In England, your type appears in your donor account after your first donation and can be viewed through the NHS Give Blood app.

The system varies slightly around the UK. Scotland’s donor accounts can show blood type, while the Welsh Blood Service sends donors a card confirming their group. Northern Ireland also tests donations for blood group.

If you’re thinking about giving blood anyway, our guide to your first blood donation explains the process. One separate issue worth knowing about is iron loss. Regular donation removes some iron along with red blood cells, so anyone already dealing with low iron or heavy menstrual bleeding should read about heavy periods and iron and check their eligibility before booking.

Can I test my blood type at home?

Yes. A home blood type test can indicate your ABO group and Rhesus D status using a finger-prick sample.

The Blood Type (A, B, O, Rhesus) Rapid Home Test Kit Rezure sells uses a test card containing reagents that react with the antigens in your blood. The resulting pattern indicates A, B, AB or O and Rh positive or Rh negative.

It’s useful when you want the information for yourself without arranging a laboratory appointment. But it shouldn’t be treated as an official transfusion result. Rezure’s product guidance states that a home result does not replace medical blood typing for transfusions, procedures or other situations where a confirmed result is required.

Technique matters too. Too little blood, incorrect mixing or mistakes when reading the card can affect the result. Our broader guide to home test reliability looks at how self-testing fits alongside professional testing.

Can I work out my blood type from my parents?

You can sometimes narrow down the possibilities, but your parents’ blood types aren’t a substitute for testing.

Blood type inheritance follows genes passed down from your biological parents. For the ABO system, you inherit one ABO allele from each parent. A person who tests as type A, for example, may have inherited AA or AO, while someone with type B may be BB or BO.

That hidden genetic difference means two parents’ visible blood groups can sometimes produce several possible baby blood types.

So a family conversation may give you clues. It can’t always answer with certainty.

The same principle applies to the Rhesus factor. A baby inherits RhD status genetically, and an RhD-positive parent can pass on genetic combinations that result in either an RhD-positive or RhD-negative child.

Will I find out my blood type during pregnancy?

Yes. Blood group testing forms part of routine antenatal care.

Pregnant women are offered blood-group testing because RhD compatibility can matter during pregnancy. If you’re RhD negative and the baby is RhD positive, exposure to the baby’s blood can sometimes lead your immune system to produce antibodies against RhD-positive red cells.

NHS screening and treatment are designed to reduce the risk of haemolytic disease of the fetus and newborn.

The first antenatal blood test is normally offered at around 8 to 12 weeks and includes screening relevant to this risk.

Pregnancy can bring other blood-related questions too. Tiredness and breathlessness aren’t explained by blood type, and iron deficiency is common enough to deserve separate attention, particularly when pregnancy follows a history of heavy periods.

Rezure’s guide to iron and anaemia myths explains the difference between low iron and anaemia.

What should I do if two blood type results disagree?

Don’t guess which one is right.

An unclear home result should be repeated according to the kit instructions. If two results conflict, or you need your blood group for pregnancy, surgery, transfusion or another medical purpose, have it confirmed through an appropriate healthcare service.

Hospitals will perform their own blood grouping and compatibility checks before transfusion rather than relying on a previous home result or your memory.