Yes for pedigree animals you can order replica tags - I have done so from Shearwell for both my goats (regularly) and sheep (as bought in ewes always seem to loose one or both of their tags, but the ones I insert stay in!).
Just make sure your numbers are correct - they will check against the DEFRA database - one of my pedigree certificates had the wrong flock number on it and the DEFRA lady had her knickers in a mighty twist... several phone calls later it was resolved (and I got a new pedigree certificate
)