In an emergency always call 999
An emergency is when a crime is happening, someone suspected of a crime is nearby, or someone is injured, being threatened or in danger.
e.g. - If your house is being burgled (or the suspect is nearby) call 999
If your car is being stolen (or the suspect is nearby) call 999
If it’s not an emergency call 101 this is London's new non emergency contact number should you need to report a crime that has occurred.
Crimestoppers 0800 555 111
If you have information about a crime but would prefer not to speak to police, you can call Crimestoppers anonymously.
Crimestoppers is an independent charity. http://www.crimestoppers-uk.org
Do not use the Neighbourhood Watch telephone number for the office in Sutton Police Station as it is not checked daily