The eGov Register uses WGS84 decimal latitude and longitude to identify locations with appropriate precision.

We currently prefer to use Paul Neave's FlashEarth to obtain lat/long values because it allows you to easily switch between Google and Microsoft aerial imagery.

1. Your PC must have Flash installed. Start up FlashEarth - this sample URL will centre on Brent Town Hall http://www.flashearth.com/?lat=51.5665&lon=-0.274&z=19

2. Click on the black intro panel to clear it.

3. Enter the postcode of the location you want in the "Search for a location box" and click to go to this location

4. Drag the image until the cross hairs are centred on the precise location that you want. Try other map providers if this is helpful.

5. Click on the "Link to this location" icon to change the URL.

6. Extract the lat/long values from the new URL in the address bar - or just email the complete URL to us if you wish to update an eGR geocode.

For more details about eGR map URLs see http://www.brent.gov.uk/egr.nsf/documents/URLs+for+Maps+and+Journey+Planners