Most national and local recording groups send their data to the Biological Records Centre (www.brc.ac.uk). Many of the more difficult to identify species groups do not have a local contact. For details of all national recording schemes visit: www.brc.ac.uk/recording_schemes.asp
Much of the data the BRC collects is made available to view by the National Biodiversity Network (NBN) through their 'NBN Gateway'.
For more information check the NBN web site (www.nbn.org.uk) or the NBN Gateway (www.searchnbn.net).