V55/5 boxes

What if the engine number is missing or changed?

Reviewed 2026-07-10

Short answer

Use the real engine number if there is one. If the engine has changed or the number is missing, gather evidence rather than guessing.

Official position

V55/5 box 33 asks for the engine number. DVLA may inspect vehicles and expects evidence when vehicle details have changed. For reconstructed or rebuilt vehicles, official receipts and parts evidence can matter.

What to do

Check the engine stamping and any foreign registration, title, MOT or approval evidence.

If the engine has been replaced, keep invoices or receipts for the replacement engine.

Do not copy an engine number from old paperwork if it no longer matches the vehicle.

Use a covering explanation if the engine number is genuinely unavailable or illegible.

Common mistakes

Putting the chassis number in the engine number box.
Using the old foreign document engine number after an engine swap.
Ignoring the impact of an engine change on capacity, emissions, tax class or approval evidence.