Many employers offer an enhanced sick pay entitlement but this is not mandatory.
For periods of sickness of seven days or less, the employer should obtain a self-certification form from the employee explaining their absence. From the eighth day onwards, the employee should provide a fit note (formerly a 'sick note') from their GP. Holiday continues to accrue during sickness absence, even when it is an extended absence.
The Bradford Factor (a formula used by HR departments to calculate the impact of employees’ absences on the organisation) can be useful in managing sickness absence but don’t use it in isolation, as each case should be considered on its merits.