How to Change the Engine Number on Your CR Book in Sri Lanka

How do you change the engine number on your CR book in Sri Lanka?

If you've fitted a different engine to your car, van or lorry, you cannot just drive off and forget about it. The law treats an engine swap as a change to the vehicle's "construction," which needs the Commissioner-General's written approval first, followed by an inspection by a Motor Vehicle Examiner who issues a certificate (CMT 130). That certificate, together with an application form and your old CR book, is what the RMV or Department of Motor Traffic (DMT) uses to print a new Certificate of Registration showing the new engine number.

This situation comes up a lot: a Toyota Hiace or Dyna's original engine seizes and the owner fits a reconditioned Japanese unit; a double cab's engine is swapped after an accident; or someone converts a vehicle from petrol to a different fuel type and the engine changes along with it. In every case, the paperwork has to catch up with the garage work — and it's much easier to do it in the right order.

Key facts

• Changing a vehicle's engine without approval is an offence under the Motor Traffic Act — approval must come before you fit the new engine, not after.
• The main application is CMT 72 (application for change of particulars on the Certificate of Registration).
• After the engine is fitted, a Motor Vehicle Examiner inspects it and issues CMT 130, confirming the new engine number.
• You'll need the purchase receipt/invoice for the engine, showing its engine number, plus photocopies.
• If the vehicle is leased or under a loan, the finance company's written consent is normally required too — see our leasing page if you're unsure whether your facility is still active.
• Apply through the office that issued your CR book: the Department of Motor Traffic for most provinces, or the Western Provincial RMV for Western Province-registered vehicles.
• An amendment fee applies; fees change, so confirm the current amount with RMV/DMT at the time you apply (as of October 2026).
• Until the CR book is updated, your vehicle's documents, insurance and resale paperwork don't match what's actually under the bonnet.

Do you need approval before or after fitting the new engine?

Before. The Motor Traffic Act says no person may fabricate, adapt, modify or change the construction of a motor vehicle — which covers the engine — without the Commissioner-General's prior written approval, and no one may knowingly use a vehicle that has been changed this way without that approval. In practice, many owners only discover this after the garage has already swapped the engine, usually when they go to renew the revenue licence or sell the vehicle and the numbers don't match. If you're in that position, you'll still need to go through the same process — get it regularised as soon as possible rather than leaving it.

What documents do you need to change an engine number?

At a minimum, expect to need:

• The CMT 72 application form (change of particulars)
• Your vehicle's Certificate of Registration (CR book)
• Your NIC
• The engine's purchase receipt or invoice, with photocopies, showing the engine number
• The Commissioner-General's prior approval for the installation (obtained before the swap)
• The Motor Vehicle Examiner's CMT 130 certificate, issued after inspection, confirming the engine number now matches what's been fitted
• A letter from the finance company, if the vehicle is still under a lease or hire-purchase facility

If your vehicle has one of the newer registration numbers starting with English letters, you may also need to produce the Vehicle Identity Card issued with it.

What's the step-by-step process at the RMV or DMT?

1. Apply for approval first. Before any mechanical work, submit a written request to the Commissioner-General of Motor Traffic explaining the engine change and asking for approval. Don't let the garage start work while this is pending.
2. Buy the engine properly. Get a proper invoice or receipt that records the engine number — you'll need this later, and it protects you if a question ever comes up about where the engine came from.
3. Fit the engine.
4. Get it inspected. Take the vehicle to a Motor Vehicle Examiner at the RMV/DMT. They check the engine number against your paperwork and issue the CMT 130 certificate if everything matches.
5. Submit the full set of documents — CMT 72, CR book, NIC, engine receipt, Commissioner-General's approval and the CMT 130 — to the Technical Branch of the office that registered your vehicle.
6. Pay the amendment fee. Ask the counter staff for the current amount, since fees are revised from time to time.
7. Collect your updated CR book, now showing the correct engine number.

What happens if you skip this and just drive with a mismatched engine number?

You run into trouble at several points, not just one. A police or RMV check can flag the mismatch. Renewing your revenue licence or passing an emission test can get held up if the officer notices the discrepancy. An insurer can question or refuse a claim because the insured vehicle's details, on paper, don't match what's actually in the car. And if you come to sell, a serious buyer checking the chassis and engine numbers against the CR book — something we'd always recommend before buying a vehicle — will spot it immediately and either walk away or demand a lower price to cover the hassle of sorting it out.

Does it matter if the vehicle is still on a lease?

Yes. While a leasing company's name is on the CR book, they have an interest in the vehicle's condition and configuration, so most finance companies expect to be told about — and to approve — a major mechanical change like an engine replacement. Check your facility terms, and if you're not sure what's still outstanding, our leasing calculator can help you work out where you stand before you spend money on a swap.

Does an engine swap affect how you should price or advertise the vehicle?

It can, in both directions. A well-documented, properly registered engine swap with a reconditioned unit and low mileage can be a selling point, especially if the original engine was due for major work anyway. An undocumented swap is a red flag that will cost you buyer trust and negotiating power. If you're preparing to list the vehicle, be upfront about the engine history in your ad, and use Price Check to see how similar vehicles are priced before you post your ad.

Where can you double-check the current process and fees?

Procedures and fees for changes to the Certificate of Registration are set by the Department of Motor Traffic and, for Western Province vehicles, the Provincial RMV, and both are revised from time to time. Confirm the current forms and amendment fee with the office that issued your CR book before you apply (as of October 2026). If you want to compare notes with other owners who've been through this — which garage handled the inspection cleanly, how long the approval took, what the finance company asked for — post your question on the Wahanaya forum; it's a good way to get practical, recent experience rather than guessing.

Sources

• Department of Motor Traffic Sri Lanka — Change of Attributes
• motortraffic.gov.lk — Change of Attributes
• Vehicle Colour Change Rules and RMV Procedure — motorguide.lk
• Motor Traffic Act (Consolidated 2024) — lankalaw.net