restrict shipping method by post code

Hi, I retail our coffee through the webstore. We have two shipping options - free delivery to selected local postcodes, or royal mail. Is there any way of restricting the 'free local delivery' option geogrphically by certain postcodes only? We regularly have customers order from outside the local area who choose free shipping, or if they chose to pay by apple pay I believe they don't have the option to update the shipping method without going into their apple pay account for which there is no prompt. 

It's awkward having to email them to ask them to amend or replace the order with the different shipping option, and if I don't then that is most of the profit on a single bag gone!

Thanks

As far as I am aware Shipping Rates can only be set by Shipping Zones (countries etc.). Sadly, local and regional shipping zones are only available for states and provinces in the United States and Canada. So no postcodes for the UK. 

One option I did for a client was that postcodes that were available for free delivery were set up as discount codes.