In the UK, the NHS Breast Screening Programme is one of the most effective tools we have for detecting breast cancer early — before symptoms appear, when treatment is most effective. But many women are uncertain about when they will be invited, what the process involves, and what to do if they haven't received their letter. This guide answers those questions.
What age does NHS breast screening start in the UK?
The NHS invites all women registered with a GP and aged 50–71 for a free mammogram every three years. Your first invitation will arrive automatically from your local breast screening unit — you do not need to request it. If you are aged 50–52, you may wait up to three years before your first invitation, as the programme sends letters on a rolling schedule by area.
What if I am under 50 or over 71?
- Under 40: Routine NHS mammography screening is not offered. You will be seen if you are referred urgently by a GP with a specific concern, or if you are enrolled in a high-risk monitoring programme (e.g. BRCA mutation carrier).
- Age 40–49: Not routinely screened. An NHS trial (AgeX) has been exploring extending screening to this age group. Some local areas offered it as part of the trial. Contact your GP if you have concerns or a family history.
- Age 71 and over: Routine invitations stop at 71, but you can self-refer to your local breast screening unit every three years. You are entitled to continue screening — you simply need to contact the unit yourself rather than waiting for a letter.
What happens at a breast screening appointment?
A breast screening appointment (mammogram) takes around 30 minutes in total, with the X-ray itself taking about 5–10 minutes. You will be seen by a female radiographer. Each breast is placed on the mammography machine and gently compressed between two plates to take X-ray images — usually two views of each breast. This can feel uncomfortable or mildly painful for some women, particularly in the days before a period when breasts are more sensitive, but it does not cause harm.
How long do results take?
Results are usually sent by letter within two weeks. The majority of women (around 95–97%) receive a normal result. If something needs further investigation, you will be invited back for an assessment appointment — this does not mean you have cancer. About 1 in 20 women recalled for assessment are subsequently diagnosed with breast cancer; the majority have benign findings.
What happens after an abnormal mammogram?
A recall letter asks you to attend a breast assessment centre, where you will have further imaging (additional mammogram views and/or ultrasound) and possibly a needle biopsy. The whole assessment is usually completed in one or two appointments. You will receive your results within a few days.
I haven't received my NHS screening invitation — what do I do?
If you are aged 50–71 and have not received an invitation, or if your invitation has been delayed, contact your GP or local breast screening unit directly. You can self-refer — you do not need to wait for a letter. You can find your local unit at NHS.uk. Make sure your GP has your current address so that screening letters reach you.
Should I attend even if I have no symptoms?
Yes. Screening is specifically designed to find cancer before symptoms appear, when it is smaller and more treatable. The majority of cancers found at screening are Stage I or II — the stages with the highest survival rates. Not attending because you feel well is the single most common reason women miss the opportunity to catch breast cancer early.