Shout
http://giveusashout.org | Free, confidential text-based crisis support. Text SHOUT to 85258
Samaritans
http://samaritans.org | Free, confidential listening service available 24 hours a day, 7 days a week. Call 116 123.
NHS 111
http://111.nhs.uk | Free NHS helpline. Select the mental health option for immediate telephone support without needing a GP referral.
999 / Accident & Emergency (A&E)
http://nhs.uk | If you or someone else is in immediate danger, call 999 or go to your nearest A&E