Electrical Safety 5 year Certificates, re-inspections for new tenancies?

Maintenance

Hi! I attended my regional NRLA webinar yesterday and there was a talk on 5yr Electrical Safety Certificates. It was interesting because I have 8x houses and 8x certificates. Recently one expired so I called around some electricians to get quotes for a new one. I was told on more than one occasion by these NICEIC or NAPIT registered electricians that if a tenant moves out, the 5yr certificate isn't valid & needs updating and a re-inspection would be necessary at a cost of, usually, £75. At yesterdays webinar NRLA rep said that this is not actually in the legislation. The correct process (as I understand it from what she said yesterday) is for the landlord to Risk Assess the property after a tenant moves out and document that have checked all plugs/sockets/lights etc. Then, ONLY if previous tenant has carried out any DIY to same, I would need a re-inspection by electrician. If no DIY was undertaken to electrics then the existing 5yr certificate is still valid. If this is correct then it suggests that electricians are not giving accurate advice. Is this because they do not understand legislation? Alternatively, is it attempt to upsell?

It smacks as similar to Gas Safe Engineers. Like when they say you need a carbon monoxide alarm despite not having solid fuel burner........

Anyone else had similar advice?

Can anyone clarify for definite please