Overview
Most of you will use this to update your engine size after an engine change to your Nova or Corsa, so this guide is primarily written for that. However, most of it still applies for making other changes to your vehicle details.

This is the official way update your vehicle records. Some of you may have done things differently, if so feel free to post your sucesses/fails, but please do not argue the toss with the data given here. This is how DVLA tell you to do it.


You will need:
1. V5C certificate
2. Engine number. This will be stamped on the block somewhere (note, "number" NOT "code". C20XE is NOT an engine number!)
3. Evidence of the change. Forms of evidence are detailed below.

You may also need a stamp, envelope and covering letter. And money if the tax band has changed!

Note Some people get away without providing evidence of the engine change. As this guide follows the official procedure, I have included it. I would recommend it, as not only does it cover your back if the DVLA do request it, but it also backs up the safety of the car - this can also come in useful for future resale, and insurance proof.


Method
Step 1. Record Engine Number
Before undetaking the engine change, make a note of the engine number (location will vary depending on engine, but its usually stamped on the block, near the gearbox). Its much easier to find it before you put the engine IN the car!


Step 2. Get Evidence
Once the engine change has been completed and tested, you'll need to get evidence of the work carried out. This can be in one of a number of formats, but at minimum MUST contain the engine number and capacity (cc). Ideally, for extra DVLA kudos, the evidence should also state that the work has been undertaken to a level that satisfies vehicle safety standards.

The forms of evidence that the DVLA will accept are:

a) Receipt for the replacement engine.
This would come from the garage or parts shop that supplied and fitted the engine.

b) Written evidence from the manufacturer.
This would be a letter from Vauxhall stating they have inspected the car and can confirm the change.

c) An inspection report provided for insurance purposes.
This would be an independent physical vehicle check undertaken by a recogniesd motoring body (e.g. AA or RAC vehicle check).

d) Written confirmation on headed paper from a garage if the change in engine size took place before you bought the vehicle.
This also covers the DIY jobs; a local garage will confirm the engine swap has been undertaken and is of a safe standard. You may also like to bundle this in with an MOT, if its due, as a pass will prove the car is roadworthy.

Note: if the change was done prior to you purchasing the car, and the V5C has not been updated, you may still be asked to provide evidence.


Step 3. Update the V5C.
Complete Section 7, Changes to Current Vehicle of the V5C with the new details, which at minimum must be engine number (28) and cylinder capacity (cc, 24). Sign and date the old keeper box in Section 8, Declaration.


Step 4. Inform the DVLA.
This is where things start to differ depending on what engine you have fitted.

a) If the Vehicle taxation class has NOT changed (i.e. engine size has NOT crossed the 1549cc threshold), write a brief covering letter to the DVLA explaining the change, attach the V5, evidence, put in an envelope and send to:

DVLA
Swansea
SA99 1BA

b) If the vehicle taxation class HAS changed (i.e. the engine size HAS crossed the 1549cc threshold), you will need to apply to retax the vehicle at your local DVLA office. Click here to find your local office. Whilst you can post the information to them, I would recommend visiting in person as you won't lose your documents in the post (or DVLA system), you can explain better in person, and you can tax the car there and then over the counter at the DVLA office. Note that if your car already has tax on it, you can either cancel the tax (and have a refund of the oustanding amount) and start a fresh 6/12 month duty period, OR simply pay the difference and continue with your existing duty period (you'll still be issued a new tax disc, but it will expire the same time as your existing one). The DVLA staff will let you know which you can do, and how much it would cost.


Step 5. Insurance
If you have an existing insurance policy, don't forget to inform them of the engine change. They may, or may not, require evidence of the change (in which case, you can use the same evidence required by the DVLA)