If you’re off work sick for 7 days in a row or less, your employer should not ask for medical evidence that you’ve been ill. The 7 days includes weekends, Bank Holidays and days that you don't normally work. Instead, they can ask you to confirm that you’ve been ill, by filling in a form yourself when you return to work. This is called self-certification.
Find out more about sick notes, and how to self-certify periods of illness of less that 7 days on NHS Inform.
If a sick note is requested for a period of illness of less than 7 days, as this is not legally required in the UK, the NHS does not cover the cost of this service. As a result, any patient requesting a sick note for a period of less than 7 days will be charged a private fee of £35 for the unnecessary work involved.