Fit notes and proof of sickness
Proof of sickness works in two stages. For the first 7 days of sickness, including non-working days, you self-certify: you tell your employer you are sick, and no medical certificate is needed. If you are off work for more than 7 days in a row, including non-working days, your employer can ask for a fit note. This page explains both stages, who can issue a fit note, and what else an employer can accept.
The 7-day line
Days 1 to 7, counting calendar days including weekends and days you do not work: self-certification. Day 8 onwards: your employer can ask for a fit note. Count from the first day you were sick, not from the first day SSP is paid — and under the current day-one rules those are now usually the same period, which removes a common source of miscounting.
Self-certification: the first 7 days
Self-certification means your own statement that you are unfit for work. Your employer may have its own form, or you can put it in writing yourself — form SC2 is the standard employee statement of sickness if your employer needs something in writing. Your employer cannot demand a doctor's note for the first 7 days as a condition of SSP, and cannot refuse SSP in that period merely because you have no medical evidence. What they can require is prompt notice: tell them by their deadline, or within 7 days if they have not set one.
Fit notes: after 7 days
A fit note, sometimes still called a sick note, states whether you are not fit for work, or may be fit for work subject to adjustments such as phased return, amended duties, altered hours, or workplace adaptations. It can be printed or digital. It must be issued by one of these healthcare professionals: a GP or hospital doctor, a registered nurse, an occupational therapist, a pharmacist, or a physiotherapist. Your employer cannot withhold SSP solely because a fit note arrives late — lateness and entitlement are different questions — but a missing fit note for a longer absence can lead to SSP being paused until evidence is provided, so send it as soon as you have it.
Other proof your employer can accept
If your employer agrees, you can give another appropriate form of evidence instead of a fit note, such as an Allied Health Professional Health and Work Report — for example, a return-to-work plan from a physiotherapist or occupational therapist. This flexibility matters for people whose care is led by an allied health professional rather than a GP. What an employer cannot do is demand excessive proof beyond the fit-note framework, or invent medical requirements that GOV.UK guidance does not contain. If your employer insists on evidence the rules do not require, ask for the requirement in writing and check it against GOV.UK before complying.
Fit notes, adjustments, and returning to work
A fit note that says you "may be fit for work" with adjustments is not a refusal of SSP and is not an instruction to return before you are ready. Your employer should discuss the suggested adjustments with you; if they cannot accommodate them, the fit note is treated as if it said you are not fit for work, and SSP continues on that basis. Keep copies of every fit note and every message about adjustments: if a dispute reaches HMRC, the paper trail decides it. Note also that annual leave continues to accrue while you are off sick, no matter how long you are off, and your employer cannot force you to take annual leave instead of sick leave.
Common fit-note mistakes
Counting only working days toward the 7 days, and therefore producing a fit note late — the count includes non-working days. Assuming a fit note is needed from day one — it is not, for the first 7 days. Letting a fit note lapse during a long absence without getting a new one — SSP for later weeks needs continuing evidence. And confusing a fit note with a diagnosis: a fit note addresses fitness for work, not the name of your condition, and your employer is not entitled to your full medical history as a condition of SSP.