If your information relates to an imminent threat to life or property, please contact the police on 999 or the police Anti-terrorist Hotline on 0800 789 321
We are responsible for protecting against threats to national security, such as terrorism. If you know something about a threat to national security, we want to hear from you.
Your message will be sent over a secure Internet connection*. You can choose to remain anonymous, but you may wish to include contact details so that we can get back to you if necessary.
Continue to the contact form.
* Your message will be sent via a Secure Socket Layer (SSL), a protocol used for secure communications over the Internet. Web addresses that begin with "https" indicate that an SSL connection will be used.
You can write to the following address:
The Enquiries Desk
PO Box 3255
London SW1P 1AE
You can tell us your information by calling our phone line on 020 7930 9000 (Please do not use the phone line for making general or recruitment enquiries - the Contact Us page tells you where to direct these).