Fit to fly letters, What they cost, and who actually needs one
Sep 3
Every year, travellers are turned away at the gate not because they are necessarily unfit to fly, but because they are carrying the wrong paperwork, or none at all. Most passengers never need medical documentation to board a commercial flight. But pregnancy beyond a certain gestation, recent surgery, a recent fracture or plaster cast, a recent heart attack, stroke or blood clot, and a range of other medical conditions can trigger an airline's medical clearance policy. The difficulty is that there is no single universal fit-to-fly rule. Airlines set their own requirements around timing, wording and documentation, and some require their own medical clearance form rather than a doctor's letter.
What matters is therefore not simply having something signed by a doctor. It is whether the document answers the specific questions the airline is asking and whether the doctor has properly assessed the passenger before confirming fitness to travel. At The Wellness, a fit to fly letter is from £250, while completion of an airline's own medical clearance form, such as a MEDIF, is from £300. Fees appear further down this page.
Reviewed by the medical team at The Wellness. Last updated September 2026.
Book a fit to fly assessment on WhatsApp or email team@thewellnesslondon.com.
Why airlines ask for medical clearance at all
Commercial aircraft cabins are pressurised, but not to sea-level conditions. Cabin pressure during flight typically corresponds to an altitude of roughly 6,000 to 8,000 feet, reducing the amount of oxygen available in the blood.
For most healthy passengers, the effect is barely noticeable. For someone with unstable cardiac or respiratory disease, a recent blood clot, severe anaemia, certain recent operations or a condition that could deteriorate unexpectedly during a flight, it can be clinically significant. That is why airlines sometimes require medical clearance rather than leaving the assessment entirely to the passenger.
Pregnancy is one of the most common reasons an otherwise healthy traveller may be asked for documentation. Many UK airlines permit uncomplicated pregnancy without a medical letter until around 28 weeks, after which they may require confirmation of the expected due date, gestation and absence of complications. Travel is commonly restricted later in pregnancy, often around 36 weeks for a single pregnancy and earlier for multiple pregnancies. The precise limits vary between airlines and routes, which is why passengers should always check the policy of the airline they are actually travelling with.
Recent surgery and injury are another common reason for medical clearance. Abdominal or chest surgery, some forms of eye surgery involving intraocular gas, and procedures where trapped gas may remain in the body can be affected by changes in cabin pressure. Fractures and plaster casts may also trigger airline-specific restrictions.
In these situations, the relevant question is not simply “Do I feel well enough to fly?” It is whether there is a medical reason that flying at that particular stage of recovery could create additional risk.
Book a fit to fly assessment on WhatsApp or email team@thewellnesslondon.com.
The difference between a fit to fly letter and a MEDIF form
A fit to fly letter and an airline medical clearance form are not necessarily interchangeable. A fit to fly letter is a doctor's written statement, normally produced on headed paper, confirming that a named patient has been assessed and is considered medically fit to travel.
Depending on the circumstances, it may include the relevant diagnosis or medical history, the planned date or route of travel and any practical requirements such as wheelchair assistance, a travelling companion or supplemental oxygen. This is commonly the type of documentation requested for pregnancy, recent injury or situations where an airline has simply asked for medical confirmation that a passenger is fit to fly.
A MEDIF, or Medical Information Form, is different. It is the airline's own structured medical clearance document. These forms can ask for detailed information about diagnosis, treatment, prognosis, mobility, oxygen requirements and the likelihood that medical assistance will be required during the journey. They generally need to be submitted to the airline's medical team in advance of travel rather than simply being carried to the airport. Completing one properly can therefore take considerably more clinical work than writing a straightforward fit to fly letter, which is why the two services are priced differently.
The critical point is to establish which document your airline actually requires before the appointment. Turning up at the airport with a doctor's letter when the airline has specifically requested its own MEDIF can create problems regardless of how well written the letter is.
Book a fit to fly assessment on WhatsApp or email team@thewellnesslondon.com.
What actually goes wrong at the gate
The most useful fit to fly document is not necessarily the longest one. It is the one that gives the airline the information it has asked for, in the format and timeframe it requires. Problems can arise when a letter is dated too far in advance and no longer reflects the passenger's current medical condition.
A letter may confirm that someone is generally well but fail to state the diagnosis, gestation, travel date or other specific information that airline staff have been instructed to check. Someone may arrive with a generic doctor's letter despite having been specifically told by the airline that a MEDIF is required.
And sometimes the medical documentation itself is appropriate, but the request has been left too late for the airline's medical department to review it before departure. For that reason, passengers who think they may require medical clearance should check with their airline as early as reasonably possible, particularly where the airline has requested one of its own forms. An appropriate clinical assessment and correctly completed documentation can substantially reduce the risk of problems at check-in, but no doctor can guarantee that an airline will allow a passenger to board. The final decision remains with the airline and, where relevant, its medical team.
What fit to fly documentation costs at The Wellness
Private medical clearance in London varies considerably depending on whether someone simply requires a straightforward assessment and letter or has a more complex condition requiring specialist input. Consultant assessment for complex fitness-to-travel cases in areas such as cardiology or respiratory medicine can cost several hundred pounds before additional investigations or documentation are added.
At The Wellness, the assessment and paperwork are arranged as part of one process.
Fit to fly letter: from £250. For patients who require a medical assessment followed by a doctor's letter confirming fitness to travel, including circumstances such as pregnancy, recent surgery, injury or an existing medical condition.
Airline medical form / MEDIF completion: from £300. For patients whose airline requires its own structured medical clearance form to be completed by a doctor.
Same-day and next-day appointments are available seven days a week in Marylebone, three minutes from Baker Street, subject to clinical and appointment availability. Where appropriate, the medical team can also help establish the clinical information an airline is requesting. Final submission deadlines and acceptance of the documentation remain the responsibility of the airline. The distinction matters because there is little benefit in paying for a doctor's letter if the carrier requires a MEDIF, just as there is little reason to complete a more involved airline form when a straightforward letter is all that is required.
Book a fit to fly assessment on WhatsApp or email team@thewellnesslondon.com.
What to check before arranging a fit to fly assessment
First, check the medical information section of the airline's own website rather than relying on a generic travel website or a policy belonging to another carrier.
Find out whether the airline wants a fit to fly letter or its own medical clearance form.
Check how recently the document must have been issued. Pregnancy letters and documentation following recent surgery or illness may need to reflect the passenger's current condition rather than an assessment performed several weeks earlier.
If a MEDIF is required, check the airline's submission deadline. The document may need to reach its medical team several days before departure.
Have the relevant medical information available for the assessing doctor. For recent surgery, for example, this may include the date and type of procedure and relevant discharge or operative information.
And do not assume that possession of a letter overrides the airline's own medical policy. A doctor assesses medical fitness; the airline retains the ultimate decision about carriage.
Book a fit to fly assessment on WhatsApp or email team@thewellnesslondon.com.
Frequently asked questions
Do I need a fit to fly letter to travel while pregnant?
Many UK airlines permit travel without a medical letter until around 28 weeks of an uncomplicated single pregnancy, after which they may require a letter confirming gestation, expected due date and absence of complications. Travel is commonly restricted later in pregnancy, often around 36 weeks for a single pregnancy and earlier for multiple pregnancies. Requirements differ between airlines, so you should always check your carrier's specific policy.
What is the difference between a fit to fly letter and a MEDIF form?
A fit to fly letter is a doctor's written statement confirming that someone has been medically assessed and is considered fit to travel. A MEDIF is the airline's own detailed medical clearance form and may require information about diagnosis, treatment, mobility, prognosis or oxygen requirements before being reviewed by the airline's medical team.
How soon before my flight should I get a fit to fly letter?
It should generally be close enough to the departure date to reflect your current medical condition while still leaving sufficient time for the airline to review any documentation it requires. If a MEDIF needs to be submitted to the airline's medical team, it is particularly important not to leave the assessment until the day before travel.
Can you guarantee that the airline will accept my letter?
No doctor can guarantee that an airline will accept medical documentation or permit boarding because the final decision belongs to the airline. A proper clinical assessment and a document completed in the format the airline has requested can, however, reduce the risk of avoidable problems.
What conditions commonly require a fit to fly letter?
Examples include pregnancy beyond certain gestations, recent surgery, fractures or plaster casts, recent heart attack or stroke, recent blood clots, significant respiratory or cardiac conditions and other circumstances where the airline's policy requires medical clearance.
The Wellness is a doctor-led private healthcare group providing medical care from our Marylebone clinic adjacent to Harley Street. All doctors are GMC-registered. Fit to fly letters and airline medical forms are issued following an individual clinical assessment. Final acceptance of any letter or form remains at the discretion of the airline. This article provides general information and is not a substitute for individual medical advice or the published medical policy of your airline.
Enquire about a fit to fly letter or MEDIF form on WhatsApp, email team@thewellnesslondon.com.
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