Buyer gave wrong postcode and items didn't arrive, where do I stand?

[123-cavaliers]

I used the postcode in the buyer's  address on their Ebay account, but the items didn't arrive (posted a month ago). Now the buyer is telling me it could be one of two different postcodes, as it's a new area. When I Googled, the postcode showing for their address, is the one I sent the items to. Where do I stand here, am I liable to give them a refund? Any help appreciated, thanks.

[cam-2793]

For future reference, eBay will usually cover item not received cases if you can prove ( via tracking) that you shipped within your stated Handling time and it was then lost by the carrier.

If it's a low value item maybe take the risk but for small but not cheap, pay for tracked envelope.