Not everyone needs a fit to fly letter — but if your airline is asking for one, you need it quickly. Lambert Medical Practice in Surbiton offers same-week assessments and certificates.
Most passengers travel by air without any medical documentation. But there are specific situations where airlines, travel insurers, or international entry requirements ask for a medical letter — and when they do, the question is not just whether you are fit to fly, but how to get the paperwork sorted before your departure date.
At Lambert Medical Practice in Surbiton, fit to fly certificates are one of the most frequently requested documents from our GP team. This guide explains when a fit to fly letter is actually needed, what the assessment involves, what airlines typically want to see in the letter, and how quickly we can arrange this for you.
A fit to fly certificate (or fit to fly letter) is a document written by a registered medical practitioner confirming that a patient is medically fit to travel by air. Airlines, cruise companies and travel insurers request these for passengers who have a medical condition or have recently had a procedure that could affect their safety or comfort in-flight.
The document is not a standard NHS form — there is no single template required by all airlines. It is a letter written on headed paper by a GP or hospital doctor, confirming the patient's condition and fitness to travel, and specifying any requirements or precautions for the journey.
Most airlines require a letter if you have had surgery within the past 10 days. This includes laparoscopic procedures, joint replacements, abdominal surgery and caesarean sections. The letter confirms wounds are healing and there is no risk of decompression complications from cabin pressure changes.
Most airlines accept travel up to 28 weeks without documentation, but require a letter between 28–36 weeks confirming gestation and that there are no complications. After 36 weeks, most airlines will not carry a passenger at all. Check your airline's specific policy — it varies significantly.
Patients with heart failure, recent myocardial infarction, significant arrhythmia, or who travel with a pacemaker or ICD may need clearance. Most airlines require a letter after a heart attack or cardiac procedure within the past 6 weeks.
Patients with COPD, severe asthma, pulmonary fibrosis, or who require supplemental oxygen may need in-flight oxygen arranged via the airline, which requires a medical letter specifying flow rate requirements. Cabin air is at approximately 75% of sea-level oxygen pressure — this is relevant for patients near the threshold of respiratory adequacy.
A fresh plaster cast in a sealed, non-bivalved state traps gases — cabin pressure changes can cause the cast to feel tight. Airlines typically require a letter, and the IATA recommendation is to split (bivalve) casts more than 48 hours old before flight. Your GP letter should address this.
If you have been discharged from hospital within the past 2 weeks — for any reason — most airlines will require documentation confirming you are fit to travel. The letter should come from a treating clinician or your GP who has reviewed the discharge summary.
If your departure is in the next few days, here is the fastest pathway:
While each airline has slightly different requirements, a comprehensive fit to fly letter from Lambert Medical typically includes:
Letters are dated within 7–14 days of flight date to remain valid. If your situation changes or you require a letter for a rescheduled flight, a brief follow-up appointment may be needed.
NHS GPs can and do write fit to fly letters, but they are not obligated to do so and may charge an administrative fee (typically £30–£80). The challenge is waiting time — with NHS appointment availability often stretching to 2–4 weeks, this is not always feasible when travel is imminent. Many NHS GPs also do not offer urgent administrative appointments in the same way private GPs do.
A private GP appointment at Lambert Medical Practice gives you a confirmed same-day or next-day slot, the full 20–30 minutes needed to complete a thorough assessment, and the letter produced at or shortly after the appointment.
Same-day and next-day appointments. Letter provided at the appointment for most cases. Lambert Medical Practice — 380 Ewell Road, Surbiton KT6 7BE.
Also at Lambert Medical: Fit to fly service page · Private GP Surbiton · When to book a private GP appointment