Just a word of warning - using local register offices to get civil registration certificates is becoming trickier, mainly due to local government budget cuts. Some require you to know certain information (like the precise date of the event, or the exact venue of the marriage) before they will supply the certificate. Many now charge a hefty supplementary fee for a same day service. So it is normally easier to order direct from the GRO. The price of certificates is set by law at £9.00. The GRO charge 25p postage to anywhere in the world. Many local register offices charge a higher postage.