On this page
- What should you tell the insurer?
- Keep three questions separate
- A like-for-like replacement still needs a clear description
- A message you can adapt
- If you are buying a car with a replacement engine
- Insurance and registration are separate tasks
- If a claim or disclosure decision is disputed
- Sources and further reading
- Related guides
Start hereIf an engine has been changed or you are planning work, ask the insurer how it wants the change described and obtain a written response before relying on an assumption about cover.
What should you tell the insurer?
Describe the work accurately rather than asking only whether “an engine code is allowed”. Useful details can include whether the replacement matches the previous specification, whether capacity or output is changing, and whether tuning or other modifications are included.
The Financial Ombudsman Service advises checking policy requirements and discussing modifications with the insurer. It also explains that outcomes depend on the circumstances. A general statement that every undeclared change automatically voids all cover would be too broad.
Keep three questions separate
| Question | What to clarify |
|---|---|
| Does the insurer accept the vehicle as described? | The actual engine, work and any conditions |
| What happens to the premium or terms? | Any revised charge, restriction or requirement |
| What value or equipment is covered? | Whether the work changes the insured value or the basis of settlement |
A garage invoice is not written confirmation from the insurer. Nor does paying for an engine necessarily mean the vehicle's insured value rises by the same amount.
A like-for-like replacement still needs a clear description
“Like for like” can mean different things to the owner, garage and insurer. Explain what is being replaced and whether the specification or vehicle use changes. Let the insurer tell you how its policy treats the work.
If you do not know the exact replacement designation, say so and ask the supplier to provide the information. Do not select a plausible code in a form just to complete the submission.
A message you can adapt
My vehicle is [make/model/year]. It currently has [engine details, if confirmed]. The proposed/completed work is [accurate description]. The supplier describes the replacement as [designation/specification]. Please confirm whether you need any further information, whether the change is accepted under my policy and whether any terms or value assumptions change.
Send necessary identifiers through the insurer's secure/private route, not a public comment. Keep its response with the work's invoice and specification.
If you are buying a car with a replacement engine
Ask the seller what changed and request the relevant paperwork. Tell the insurer what you know and what remains uncertain. Do not rely on the seller's experience with a different policy or on a generic registration lookup that may reflect an earlier specification.
Our used-car engine verification guide provides a way to record those evidence gaps before purchase.
Insurance and registration are separate tasks
An insurer accepting a change does not itself update DVLA's records. Equally, a V5C amendment is not an insurer's agreement to cover the vehicle. See engine changes and DVLA records.
If a claim or disclosure decision is disputed
Ask the insurer to explain the relevant policy term, question, evidence and decision. Use its complaint process and check the Financial Ombudsman Service's current eligibility and referral information if needed. This guide does not decide the outcome of an individual claim or replace policy-specific advice.