How to self certify sickness at work

Self-certifying sickness in the UK covers the first seven calendar days of an absence and requires no doctor and no medical evidence (gov.uk). The seven days are counted on the calendar, weekends and bank holidays included, so the right to self-certify runs out at the start of day eight (Acas).

For most absences this is the whole process, because short illnesses make up the bulk of sickness at work. The steps below set out how an employee self-certifies, what an employer should ask for, and where statutory sick pay fits in.

Key takeaways

• Self-certification covers the first seven calendar days of sickness with no medical evidence.
• The employee must notify the employer by the deadline the employer has set.
• On return, the employee confirms the dates and a general reason in writing.
• Statutory sick pay is due from day one of the absence for eligible employees.
• A fit note replaces self-certification from day eight onward.

Step one: notify the employer promptly

The first step is telling the employer about the absence. An employer can set a deadline for notification, but it cannot be earlier than the first qualifying day of sickness, and if no deadline is set the employee must report within seven days (gov.uk). Many workplaces ask for a call or message before the start of the shift.

Notification protects pay. Where an employee fails to follow a reasonable procedure without good reason, an employer may be entitled to withhold statutory sick pay for the late days (gov.uk). Clear absence rules in the contract or handbook keep this straightforward for both sides.

Step two: cover the first seven calendar days

During the first seven calendar days, no fit note is needed. The employee self-certifies, meaning they confirm to the employer that they were too unwell to work (Acas). The count is in calendar days, so an absence beginning on a Wednesday reaches day seven on the following Tuesday regardless of which days the employee was rostered.

This window exists so that short, self-limiting illnesses do not clog GP appointments. The employee does not have to explain symptoms in detail, only that they were unfit for work (gov.uk). An employer running payroll in-house still records these days, because they feed the sick pay calculation in modern payroll software, and the same applies to the smallest small business payroll.

Step three: confirm the absence on return

When the employee returns, the employer usually asks them to confirm the absence in writing. This is the self-certification itself, and the employer and employee agree how it is done, whether on form SC2, an in-house form, or a logged return-to-work conversation (gov.uk).

The confirmation should record the dates and a general reason, nothing more. Health data is special category data under UK GDPR, so an employer must not demand detailed medical information at this stage (Acas). A bureau handling this across many employers keeps the fields consistent on a multi-client payroll dashboard.

Step four: switch to a fit note from day eight

If the absence continues past seven calendar days, self-certification ends and a fit note is required (gov.uk). The employee should obtain one from a doctor, nurse, pharmacist, physiotherapist or occupational therapist and pass it to the employer on the seventh day or as soon as possible after (gov.uk).

Throughout the absence, statutory sick pay runs from the first qualifying day, since the 2026 SSP reform removed the three waiting days that used to delay it (Acas). Payroll platforms built on an HMRC-recognised payroll API apply this day-one rule automatically and report the payment through Real Time Information.

Conclusion

Self-certifying sickness comes down to four simple moves: tell the employer in time, cover the first seven calendar days without a doctor, confirm the dates on return, and switch to a fit note if the illness runs longer. The detail that catches people out is the calendar-day count, which keeps ticking through weekends and bank holidays.

Since sick pay now starts on day one, even a single day of self-certified absence can carry a statutory payment. Keeping the notification and confirmation tidy is what keeps that payment correct and the absence record clean.

Frequently asked questions

How do you self-certify sickness in the UK?

The employee notifies the employer of the absence, then confirms the dates and a general reason on return, usually on form SC2 or an in-house form (gov.uk). No medical evidence is needed for the first seven calendar days. A fit note is required only if the absence lasts longer.

How many days can you self-certify before needing a sick note?

Self-certification covers up to seven calendar days, including weekends and non-working days (Acas). From day eight, a fit note from a registered healthcare professional is needed. The employee should give the fit note to the employer on the seventh day or as soon as possible afterwards.

Do you get paid while self-certifying sickness?

Eligible employees receive statutory sick pay from the first day of sickness, including during the self-certification period (Acas). The three waiting days were removed by the 2026 reform. Some employers also offer contractual sick pay, which must be at least as much as the statutory minimum, and one-off employers can produce a compliant payslip through the Instant Payslip Generator.

Can an employer refuse to accept self-certification?

An employer cannot require medical evidence for an absence of seven calendar days or fewer, so it cannot insist on a fit note in that window (gov.uk). It can, however, withhold statutory sick pay where the employee fails to follow a reasonable notification procedure without good reason (gov.uk).