(Public Service Announcement)
Renewal of your EHIC (European Health Insurance Card - which replaced the old E111 form) is always FREE. I say again, there is NO CHARGE to renew your EHIC, ever. Any website which charges you a fee to renew, for any reason, is ripping you off.
They just pocket your money and pass on your form to the proper, free NHS site. They may claim to "check your application for mistakes", but really, how would they know if you wrote your name wrong on the form? It will just take longer because it has to go through them first before it reaches the genuine NHS site; you might as well send it directly for free. And don't fall for the "fast track" or "express" scam either. That just means they sit on your form slightly less before passing it on into the exact same NHS processing queue.