You do not require an NHS fit note if you have been absent from work for 7 days or less, you can complete a self-certification form yourself.
Many employers have their own self-certification forms and processes. If your employer does not have their own form, you can use the government SC2 self-certificate.
If your employer insists on obtaining a fit note before you have self-certified, we may be able to issue you with a private fit note. This is non-NHS work so you would incur a fee – please discuss this with your employer as they may agree to meet the remittance.