What is this?
Every consumer unit should have a clear schedule (chart) showing which MCB or fuse controls which circuit. BS 7671 requires this as part of any electrical installation. When labels are missing or incorrect, you cannot identify which circuit to turn off in an emergency, which makes fault-finding difficult and emergency isolation potentially dangerous. Unlabelled boards are common in older installations or where work has been done without proper documentation.
Common causes
- Labels were never fitted after the original installation or upgrade
- Circuit schedule has faded, fallen off, or been painted over
- Circuits have been added or changed without updating the labels
- DIY work has rearranged circuits without documentation
- Labels were fitted but are inaccurate due to changes over time
Is it dangerous?
Missing labels are a low-level safety issue in normal use, but they become a serious problem in an emergency. If you need to quickly isolate a specific circuit — for example, when someone is receiving an electric shock or there is a fault on one circuit — incorrect or missing labels mean you cannot identify the right switch. In an emergency, you may have to turn off the main switch, cutting all power.
Can I fix it myself?
You can attempt to identify circuits yourself by switching off each MCB one at a time and checking which lights, sockets, or appliances lose power. However, this takes time and you may miss circuits or make errors. A professional circuit identification and labelling is more reliable and includes proper testing.
When to call an electrician
Ask your electrician to label the board during any visit, as it is usually a quick addition to any job. A dedicated circuit identification visit is worthwhile if you have no idea what any of the switches control, or if an EICR has flagged the lack of labelling.
What will an electrician do?
Systematically identify every circuit by testing and isolation
Create and fit a circuit schedule (chart) on or near the consumer unit
Check that all circuits are on the correct rated MCB
Note any anomalies found during identification (shared circuits, unlisted circuits)
Typical cost
£60 – £150
Circuit identification and labelling is a quick job in most homes. Costs are at the lower end for standard installations with fewer than 10 circuits.
