Hello there.

For T5 to T5 connections:

Arrive Domestic:

Arrive in gates A1 to A7 (or something like that)
Follow purple signs to escalator of progress
Show BP
Go up escalator
Hey Presto!!!

Arrive International

Option 1
Arrive in any other A gate
Go to Flight Connections Centre
For UK Follow signs to Zone A
-Conformance check
-Passport control
-Photopoint
-Security (North)
For other connections go to Zone B (Fasttrack is available)
-Passport control
-Security (North)

Option 2
-Arrive B Gate
-Check if flight is on Time Critical Connection Board. If so follow signs to B gates.
-Otherwise take train to Flight Connections Centre as option 1.