This information has been revised on 6th August 2007 after going through the necessary procedures to obtain a certificate.The ex-16 form for the residency certificate can be downloaded from
http://www.crm.es/VisitorsOnly/Documents/ex16.pdfInformation from the British Embassy can be found on
http://www.britishembassy.gov.uk/servlet/Front?pagename=OpenMarket/Xcelerate/ShowPage&c=Page&cid=1150455474963You will need to obtain the form (modelo 790 - codigo 012) to pay. This will be given to you at the Police Station and you have to go to pay at the nearest bank (near the Red Cross building) The amount is €6.70. If anyone can find this form on the internet please add the relevant link.
Documents required in addition to these are your passport & old residencia card. If you wish to keep your old residencia card I would suggest that you do not present it to them unless asked for it, otherwise they will keep it. If you do not have an expired residencia card you may need a Certificate of Empadronamiento from the Town Hall. These can be presented in person at Denia Police station.
When queuing (on the main road side) at Denia Police Station be sure to get a ticket number for 'Extranjeros'. Present your documents and take the form 790 to the bank. When you return you will not need another ticket and will be allowed to go straight in to the office to receive your certificate.
The office is open from 09:00 to 14:00 Mondays to Fridays.