Older classics can be exempt from both the annual MOT test and road tax (Vehicle Excise Duty) under the UK’s rolling “40-year rule” — but neither exemption is automatic, and both depend on a “substantial changes” test that catches modified cars. Here’s how it actually works, written for owners.
The 40-year rolling rule, in brief
Two separate exemptions run on the same rolling 40-year threshold: exemption from the annual MOT test, and exemption from road tax (VED), where the vehicle moves into the “Historic” tax class at a £0 rate. The rule is “rolling” — it’s tied to your car’s date of first registration or manufacture, not a fixed year, so a new band of cars becomes eligible every year. As of 2026, vehicles first registered or built before 1 January 1986 qualify; in 2027 the line moves to 1 January 1987, and so on. (The MOT exemption in its current form dates from 20 May 2018; the rolling VED exemption from 2014.) These rules apply in Great Britain; Northern Ireland and imported vehicles can differ, so check your own case.
It is not automatic — you have to declare it
Reaching 40 doesn’t exempt your car by itself; you have to make a positive declaration. For the MOT, you confirm the exemption when you tax the vehicle, completing form V112 (“Declaration of exemption from MOT”) — or V112G for goods vehicles. For road tax, you must apply to change the tax class to “Historic”; the first time you do this it has to be done in person at a Post Office (with your V5C log book, and your MOT certificate or V112), after which you re-tax each year at £0 — you still “tax” the car, it’s just free. Miss the declaration and DVLA will still expect a valid MOT.
The “substantial changes” test — the crucial part
Both exemptions only apply if the vehicle has not been “substantially changed” in the previous 30 years. DVSA and DVLA set this out in detail, but broadly a car is considered substantially changed if, for example, the chassis or monocoque bodyshell has been replaced (rather than repaired), the body has been significantly altered, the axles or running gear have been changed in a way that alters the steering, suspension or braking, or the engine has been swapped for one of a different type or capacity. Crucially, routine maintenance and like-for-like restoration don’t count — engine rebuilds, panel replacement, a suspension refresh, or fitting a same-specification replacement are all fine — and changes made purely to improve safety, efficiency or emissions are generally allowed. But a genuinely modified car — a different-capacity or different-type engine, or altered running gear that changes how the car drives — can fall outside the exemption and will still legally need an annual MOT. It’s a self-declaration (DVLA doesn’t inspect your garage), so the responsibility, and the honesty, rests with you.
Road tax: the Historic vehicle class
Once eligible, your car can move into the “Historic” VED class and be taxed at £0. As with the MOT, you apply for it — it isn’t applied for you — and the change becomes effective from the start of the tax year (around 1 April) for vehicles built before 1 January forty years earlier. You’ll receive an updated V5C confirming the new tax class, and thereafter you re-tax annually at no cost. If you’re buying a car that’s already over 40, it’s worth checking the seller has actually made the change, so you’re not caught out.
What still applies, exempt or not
Exemption from testing is not exemption from responsibility. Whether or not your car needs an MOT, the law still requires it to be roadworthy and properly maintained, road-legal tyres and lights still apply, and it must be taxed (even at £0) and insured to use on the road. Many owners of exempt cars choose to have a voluntary MOT anyway — for peace of mind, for the insurance benefits, and because a recent MOT history reassures buyers when it’s time to sell.
For your MG T-Series
MG T-Types — the TC, TD and TF, built between roughly 1945 and 1955 — are all comfortably past 40, so they qualify on age, and as largely original cars most sail through the substantial-changes test. The point to watch is modification: a five-speed gearbox conversion, a significantly altered engine or uprated running gear are common on T-types and, if extensive, could bear on whether the car still counts as unmodified. If yours is heavily modified, consider whether it truly qualifies — and a voluntary MOT is never a bad idea. If in doubt, check the current guidance for your exact vehicle on GOV.UK.
Frequently asked questions
- When is my classic car MOT exempt?
- When it was first registered or built more than 40 years ago (before 1 January 1986 for 2026) and hasn't been substantially changed in the last 30 years — and you've declared the exemption when taxing it.
- Is the exemption automatic?
- No. You must declare MOT exemption on form V112 when taxing, and apply to move the car into the Historic tax class (the first time, at a Post Office).
- What counts as a "substantial change"?
- Broadly, replacing the chassis or bodyshell, major body alterations, changing the axles or running gear to alter how it drives, or fitting a different type or capacity of engine. Like-for-like restoration and safety improvements don't count.
- Does an exempt car still need tax and insurance?
- Yes. It must still be taxed (at £0 in the Historic class) and insured, and kept roadworthy, to be used on the road.
- Does the year change?
- Yes, it rolls forward by one year every year. Always check the current position on GOV.UK.
The official guidance
The rules roll forward and the detail can change. For the current position on historic vehicles, MOT exemption and the Historic tax class, read the official guidance: gov.uk/historic-vehicles.
Read next
Last reviewed 2026-07-17