Flying with an infectious illness
Airlines can refuse any passenger who appears infectious. For some illnesses they publish exact waiting periods; for others it is a judgement call at the gate.
The short answer. It depends on the illness and the airline. Carriers publish specific waiting periods for measles and chickenpox, and several require a doctor’s letter confirming you are no longer contagious. For everything else the working rule is simple: you may travel when you are no longer infectious — but a visibly unwell passenger can be refused boarding.
Published airline waiting periods
| Airline | Measles | Chickenpox | Letter required? |
|---|---|---|---|
| easyJet | 7 days after the rash | 7 days after the last new spot | No |
| Jet2 | 6 days after the rash | 7 days after the last new spot | No |
| Ryanair | 7 days after the rash | 7 days after the last new spot | Yes |
| British Airways | 5 days after the rash | 6 days after the last new spot | Yes |
Two rules operate at once
The published rule. For a handful of named illnesses, airlines set exact waiting periods in their conditions of carriage. Measles and chickenpox are the two that appear most consistently, and Jet2, easyJet, Ryanair and British Airways all publish figures for them.
The discretionary rule. Airlines reserve the right to refuse anyone who appears to be suffering from an infectious disease. Ryanair states it directly: if there is reason to believe you have an infectious disease or a visible skin condition, you may be asked to produce a medical certificate confirming you are fit to fly. In practice that decision gets made at the gate by someone who is not a clinician, which is why a letter is worth having if there is anything visible.
The illnesses people ask about
Hand, foot and mouth. Common in young children and usually mild. It is most contagious in the first week. No UK airline publishes a specific waiting period, so the discretionary rule applies — and a visible rash on the hands and face invites questions. A letter helps.
Tonsillitis. Not usually a boarding problem once you are on treatment and feeling better. The bigger issue is pain and ear congestion on descent. If you have a peritonsillar abscess (quinsy), do not fly — get it treated.
Conjunctivitis. Infectious conjunctivitis is very visible, which is exactly why it prompts questions at the gate. Bacterial conjunctivitis is generally considered non-infectious after around 24 hours of treatment; viral takes longer.
Norovirus and gastroenteritis. Airlines really do not want this on board, for obvious and practical reasons. The standard public health advice is to stay away from others until 48 hours after symptoms stop — apply the same to flying.
Flu and COVID. No blanket ban now applies, but the discretionary rule does. If you are feverish and coughing you may be refused, and you will make everyone around you miserable for the duration.
When not to fly
Do not fly with a high fever, breathlessness, a widespread new rash, persistent vomiting or diarrhoea, or if you have been told you have a notifiable infection. If you are unwell enough to be asking whether you are allowed to fly, that is usually your answer.
Common questions
Can you fly with hand foot and mouth?
No UK airline publishes a specific waiting period. It is most contagious in the first week, and a visible rash may prompt questions at the gate, so a doctor’s letter is worth having. Children are usually fine to travel once they are well and the blisters have dried.
Can you fly with tonsillitis?
Usually yes once you are on treatment and feeling better. Expect ear discomfort on descent. Do not fly with quinsy — that needs treating first.
Can you fly with conjunctivitis?
Generally yes, though it is highly visible. Bacterial conjunctivitis is usually considered non-infectious about 24 hours after starting treatment; viral takes longer to settle.
Can an airline refuse to let me board if I look ill?
Yes. Airlines reserve the right to refuse a passenger who appears to be suffering from an infectious disease, and Ryanair for one says explicitly that you may be asked for a medical certificate confirming you are fit to fly.
What about measles?
Airlines are strict. British Airways requires 5 days from the rash appearing plus a doctor’s letter confirming you are no longer contagious; Jet2 permits travel on days 6 to 14 with a fit to fly certificate; easyJet and Ryanair require 7 days from the rash appearing, with Ryanair also requiring a certificate.
Related
Sources. The airline and clinical facts on this page were checked against these primary sources on 24 August 2026. Airline policies change without notice — always confirm with your airline before you book or travel.
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