UK mail redirection. Any bright ideas?

Does anybody know what to do when Royal Mail stops redirecting mail from a UK address. They've just sent me a letter saying that it's about to expire after two years and that it cannot be extended. I'm renting my house back in UK and I've paid Royal Mail for the redirection service. Obviously not profitable enough for Royal Mail, but this must be a common enough problem for ex-pats. Any alternatives which don't involve my tenant bunging my mail into jiffy bags will be much appreciated.

Hello Sandy, thanks for the info. I’ll try that and hope for the best

Have to say, we just filled in the renewal form and it carried on being redirected …