If the premium for Group Health Insurance is paid for by your employer it counts as a P11D benefit. This means that you would be liable for tax on the premiums as it counts as a benefit in kind.
When your earnings are taxed the amount that your employer paid for the premiums is added to your earnings and you are taxed on that amount. This is all arranged by your employer with HMRC so you don’t need to do anything.
In exchange, you get access to fast treatment in top-notch facilities for any eligible medical condition you might suffer from, all of which is covered by your employer.
For more information, see our Group Health Insurance page.