The General Records Office (GRO) holds the records from 1837 and includes the civil birth, marriage or death records for England and Wales has increased the price of the documents.  The price increase is not large:

£2.50 for a digital image of a record, the GRO now charges £3. Currency exchange daily at the time of this posting one-pound sterling was equal to $1.27 (USD). 

You can order certificates online or write to:

General Register Office
PO Box 2
Southport
PR8 2JD

 For records in Scotland contact the National Records of Scotland: https://www.gov.uk/national-records-of-scotland

For records in Northern Ireland go to:  General Register Office for Northern Ireland.