EAN-13 Barcodes (or International Article Numbers) are 13 digit barcodes that are used on all products (except for books and magazines ) in the vast majority of countries internationally. The only countries where UPC barcodes are more common are the USA and Canada.
There are a couple of options for getting EAN-13 barcodes in the UK:
You could go to barcode licensing organisation and pay a joining fee and annual membership fees – however this can become expensive.