The National Flu Line can not issue medical certificates
Med 3 - only use this if you have examined the patient on the day of issue or day before.
The Department of Health is looking at it being possible to issue Med 3s after a telephone consultation only. If you do this please annotate the certificate clearly to this effect
Med 5 - you could use this without seeing the patient if you have evidence of your patient having been seen at Out of Hours or by another doctor.
Self certificates
These cover the first week of sickness leave and is designed to minimise the workload on GPs and Health Services from minor, self limiting conditions.
The employer can allow an extension on the period of self-certification e.g. 10 days during a flu pandemic when their employee has flu like symptoms. If they have access to occupational health then they can use these resources to evidence additional time off.
Useful DWP letter for employers about Employee Self Certification and SSP (Swine Flu)
Useful DWP letter for your patients (employees) about self certification and SSP (Swine flu)
Letter to give to your patient if they request a certificate for less than seven days because their employer "says so"