Grab this August/September's edition of Wedding magazine (£4.90 with brunette bride on the cover) and on p119 you'll find a voucher for 20% off at Coast, to use both online and in store.
The voucher's valid at all Coast stores in the U.K and Ireland (except factory outlets). You can't use the voucher with any other discount and unfortunately it's not valid on sale items or purchases made with gift cards/certificates.
The discount is worth it if you spend at least £25 at Coast to make up for the pricey mag. The voucher's valid until Weds 1 Sept