The short answer
There is no legal requirement to obtain a separate Electrical Installation Condition Report (EICR) before replacing a consumer unit. However, the registered electrician carrying out the replacement is required to inspect and test the existing circuits as part of the installation, and this serves much the same purpose: it establishes whether the wiring is sound enough to be certified on the new board. If faults are found, they must be put right before the Electrical Installation Certificate (EIC) can be issued. In practice, getting a separate EICR first can be useful if you want an independent view of the wiring's condition before committing to a replacement quote — particularly in older properties where remedial work costs can vary widely.
The question of whether an EICR is needed before a replacement often arises because homeowners want to avoid surprises on the day. Here is how the testing requirement works in practice, and when a prior EICR adds genuine value.
EICR and replacement
- EICR required by law before replacement?No — no legal requirement
- Testing required during replacement?Yes — circuits tested before EIC issued
- What if faults found?Must be remedied before certification
- When prior EICR is usefulOlder wiring, suspected faults, cost planning
- Certificate after replacementEIC (not an EICR)
What the electrician tests during a consumer unit replacement
When a registered electrician fits a new consumer unit, they are required by BS 7671 (the 18th Edition wiring regulations) to inspect and test each circuit connected to the new board. The tests carried out include:
- Insulation resistance: checks that the insulation on cables is sound and there are no short circuits or degraded insulation between conductors.
- Earth continuity: confirms that the earthing conductors provide an effective path to earth for each circuit.
- Polarity: verifies that live, neutral and earth connections are correct throughout.
- Prospective fault current: assesses the fault level at the board, which determines whether the protective devices are adequately rated.
- RCD / RCBO trip times: where residual-current devices are fitted, their disconnection time is tested to confirm they operate within the limits required by BS 7671.
These tests generate the recorded data that goes into the Electrical Installation Certificate. The EIC can only be issued if the circuits pass. If a circuit fails, the fault must be found and corrected before that circuit is connected to the new board and certified.
When a separate EICR before replacement makes sense
An EICR (Electrical Installation Condition Report) is a systematic inspection and test of the entire existing installation, resulting in a report that codes each issue as C1 (danger present), C2 (potentially dangerous), C3 (improvement recommended) or FI (further investigation needed). It is distinct from an EIC, which is issued for new work.
Getting an EICR before a consumer unit replacement is not required but can make practical sense in these situations:
- Older property with unknown wiring history: an EICR establishes the condition of the wiring before you commit to a replacement quote, so remedial work costs can be scoped and included up front rather than discovered on the day.
- Property purchase: if you have recently bought a house and are considering a board upgrade, an EICR gives you the full condition picture and allows you to make an informed decision about the scope and timing of work.
- Budgeting: if the wiring is in poor condition, the cost of remedial work to pass the new board's tests can be material. An EICR done separately allows you to get like-for-like quotes from different electricians for the total scope of work.
- Landlord requirements: private landlords in England are required to have an EICR carried out every five years (or at change of tenancy). If an EICR is already due, getting it done before a board replacement means the results are available to plan the replacement scope.
| Scenario | Prior EICR useful? | Reason |
|---|---|---|
| Modern home, sound wiring, recent inspection | Not essential | Replacement testing covers the circuits adequately |
| Older property, no recent inspection | Yes — useful | Identifies faults before quoting; avoids day-of surprises |
| Recent property purchase | Yes — useful | Establishes baseline condition of inherited installation |
| Rental property — EICR due | Yes — required anyway | Landlord legal obligation independent of replacement |
General guidance. A registered electrician can advise based on the property's age, wiring type and inspection history.
EICR versus EIC — what you receive and when
It is worth being clear about the difference between the two documents:
- An EICR (Electrical Installation Condition Report) is the result of inspecting and testing an existing installation to assess its condition. It does not certify new work; it reports on what is already there and codes any deficiencies. EICRs are carried out periodically (typically every ten years for an owner-occupied home, every five years for a rental) or when an installation has not been inspected recently.
- An EIC (Electrical Installation Certificate) is issued for new work — it certifies the installation that has just been completed, records the technical details and test results, and confirms compliance with BS 7671. A consumer unit replacement results in an EIC, not an EICR.
When you receive an EIC after a consumer unit replacement, it covers the new board and its connected circuits as installed and tested on the day. If the electrician had to make remedial repairs to existing wiring during the job, those repairs are noted. The EIC is the document you keep as evidence of the notifiable Part P work having been certified.
Frequently asked questions
Is an EICR legally required before a consumer unit replacement?
No. There is no legal requirement for a separate EICR before a consumer unit replacement. The electrician doing the replacement tests the circuits as part of the job. Getting an EICR first is not compulsory but can be practical in older properties with unknown wiring history.
What happens if faults are found during the consumer unit replacement?
If testing during the replacement finds faults in the existing wiring, those faults must be put right before the Electrical Installation Certificate can be issued for the new board. Minor remedials are sometimes included in the replacement quote; significant faults are usually quoted separately. It is worth asking your electrician how they would handle this before work begins.
What is the difference between an EICR and an EIC?
An EICR (Electrical Installation Condition Report) inspects an existing installation and codes any deficiencies. An EIC (Electrical Installation Certificate) is issued for new work — it certifies that the installation just completed meets BS 7671. A consumer unit replacement produces an EIC, not an EICR.
Sources & further reading
- Electrical Safety First — periodic inspection and testing
- Total Skills — electrical certificates explained (EIC, EICR, Minor Works)
- NAPIT — domestic electrical testing and inspection
Figures on this page are typical UK ranges drawn from published sources and depend on your specific property and installation. They are guidance, not a quotation.