Taxi fares across most parts of the country (outside of London) usually work out at around �2 per mile. So, based upon that, you're looking at a fare of around �28.
To be more accurate, metered taxis in Herefordshire currently charge a minimum fare of �2.40 for the first 965 metres, then 10p for every extra 90 metres (plus various minor add-ons, such as 20p for each passenger in excess of two). Taking your figure of 14 miles as being precise, that would result in a fare of �26.40.
Chris