Format of phone number in imported contacts

I created a VCF file (VCARD version 2.1) of contacts and imported it into an Android 5 phone. A Motorola Moto G 2nd generation. The VCF has phone numbers formatted correctly for the UK (e.g. "01234 567890") BEGIN:VCARD VERSION:2.1 N:;John;Smith FN:John Smith TEL;HOME;VOICE:01234 567890 REV:20150824T162717Z END:VCARD but Android has altered them to a format that looks like a US format ("012-345-67890). How can I stop this happening?