Install a prepayment meter.

While energy suppliers often install their own meters for billing, private electricians are frequently called to install secondary "sub-meters." These allow property owners to monitor and bill electricity usage for specific areas of a building independently from the main supply.

What Does the Work Involve?

• Site Assessment: Inspecting the current meter position, consumer unit, and cable thickness (meter tails).
• Safe Isolation: Turning off the mains supply and testing to ensure the circuit is dead before work begins.
• Removal & Fitting: Removing the old unit and mounting the new digital or smart payment meter.
• Wiring: Connecting the meter tails to the consumer unit and securing them with proper trunking or a meter box.
• Testing: Verifying earth continuity, RCD trip times, and ensuring the meter records usage accurately.
• Commissioning: Programming the unit, setting tariffs (for sub-meters), and demonstrating how to top up.

Typical Costs

Prices are influenced by the complexity of your existing wiring. If your consumer unit is outdated or the meter tails are too thin for modern standards, these must be replaced to comply with safety regulations.

How Long Does It Take?

• Standard Meter Swap: 1–2 hours for a straightforward replacement in an accessible location.
• New Sub-Meter Installation: 2–4 hours if new cabling needs to be run from the main distribution board.
• Complex Upgrades: 4–8 hours if the job requires a new consumer unit or significant remedial wiring.

DIY or Professional?

This is strictly a job for a qualified professional. Working with mains electricity is life-threatening if mishandled, and illegal tampering with a supplier's meter is a criminal offence.

Warning: Any electrical work in "wet zones" (kitchens/bathrooms) or involving a new circuit must comply with Part P of the Building Regulations.

Choosing the Right Tradesperson

• Check Credentials: Ensure they are registered with a UK competent person scheme like NICEIC, NAPIT, or ELECSA.
• Verify Insurance: They should hold valid Public Liability Insurance (minimum £2 million).
• Red Flags: Be wary of anyone who refuses to provide a Minor Works Certificate or offers to "bypass" a meter.

Questions to ask:

• Are you Part P registered and can you self-certify this work?
• Is the meter you are installing MID-approved (required for legal billing of tenants)?
• Will you notify the DNO (Distribution Network Operator) if the main service fuse needs to be pulled?

UK Regulations

• BS 7671 (Wiring Regs): All work must meet the current 18th Edition standards for safety and earthing.
• MID (Measuring Instruments Directive): If you are charging a tenant based on the meter readings, the meter must be MID-approved.
• Part P: Covers electrical safety in dwellings; you should receive a compliance certificate after the job.

Common Problems

• Inadequate Tails: Older properties often have 16mm tails, but modern 100A supplies usually require 25mm cables.
• Access Issues: Meters hidden behind heavy furniture or built-in cupboards can significantly increase labour time.
• Communication Errors: Smart payment meters may fail to connect to the network if installed in a basement with poor signal.
• Tamper Seals: If an electrician finds broken seals on the main fuse, they are legally required to report it to the network operator.

Frequently Asked Questions