How UK MOT pass rate decays with vehicle age

Background

UK MOT outcomes show a clear age pattern in this dataset: pass rates are highest among the youngest vehicles in scope and then weaken as vehicles get older. The series begins at age 3, where 9,410,630 tests are recorded with a 91.39 pass rate, and extends to age 30, where 62,388 tests are recorded with a 70.14 pass rate.

The central finding is not simply that older vehicles pass less often. It is that the decline is steep through the early and middle years, then becomes much flatter, and eventually reverses among the oldest vehicles still appearing in the test pool. That creates a decay curve rather than a straight line.

This report addresses the age pattern only. The findings do not include UK driving-test pass rates, MOT prices, MOT fees for 2023 or 2024, or the testing interval in the UK, so those reader questions cannot be answered from this document.

The age-by-age pattern

The broad trajectory is visible across nearly every adjacent age band from 3 through 18. At age 3, the pass rate is 91.39. By age 4 it is 89.33, at age 5 it is 87.08, and at age 6 it is 84.6. The slide continues at age 7 with 81.89 and age 8 with 78.9.

By age 9, the pass rate is 75.87, and by age 10 it is 73.09. The pattern remains downward through age 11 at 70.64, age 12 at 68.37, age 13 at 66.57, age 14 at 65.03, age 15 at 63.83, age 16 at 62.98, age 17 at 62.41, and age 18 at 62.27.

After that, the direction changes. Age 19 records 62.47, age 20 records 63.03, age 21 records 63.84, and age 22 records 64.52. The oldest ages in the file continue that upward movement, reaching 70.14 at age 30.

Key benchmark ages

Several ages stand out as useful reference points because they are also surfaced directly in the findings.

Vehicle age	Tests	Pass rate
3	9,410,630	91.39
7	9,701,249	81.89
10	7,321,317	73.09
15	5,054,033	63.83
20	1,240,327	63.03

These benchmarks show how quickly the curve moves in the first half of the age range. A vehicle at age 3 is still in very strong territory at 91.39. By age 7, the pass rate is 81.89. By age 10, it is 73.09. By age 15, it is 63.83, and at age 20 it is 63.03.

That sequence also shows the flattening effect. The movement from age 15 to age 20 is much smaller than the movement from age 3 to age 10. In other words, the early decline is the dominant feature of the dataset.

Where the decline is steepest

The steepest deterioration appears in the younger and midlife years. The run from age 3 through age 10 is especially notable because every age step is lower than the one before it, and the pass rate moves from 91.39 at age 3 to 73.09 at age 10.

A similar but gentler decline continues from age 10 through age 18. The pass rate falls from 73.09 at age 10 to 70.64 at age 11, 68.37 at age 12, 66.57 at age 13, 65.03 at age 14, 63.83 at age 15, 62.98 at age 16, 62.41 at age 17, and 62.27 at age 18.

This matters because it suggests that age-related deterioration is not evenly distributed across a vehicle’s life in the MOT system. The early years after age 3 show a strong downward slope, while the later years show a compressed range clustered around the low-to-mid 60s before the curve turns upward.

The late-life rebound

One of the most interesting features in the findings is the rebound among older vehicles. After bottoming at 62.27 at age 18, the pass rate edges up to 62.47 at age 19 and 63.03 at age 20. It then continues upward: 63.84 at age 21, 64.52 at age 22, 65.73 at age 23, 66.69 at age 24, 67.43 at age 25, 67.79 at age 26, 68.19 at age 27, 68.62 at age 28, 68.81 at age 29, and 70.14 at age 30.

That does not mean very old vehicles are easier to pass in any general sense. It means the vehicles that remain in the testing population at those ages post higher pass rates than the vehicles in the late-teen age bands. The findings show the pattern, but they do not explain the cause.

A plausible interpretation would involve survivor effects, enthusiast ownership, lower annual use, or stronger maintenance among vehicles that remain on the road into their third decade. But those explanations are outside the evidence provided here. The safe conclusion is narrower: the pass-rate decline does not continue indefinitely, and the oldest ages in the file show recovery.

Test volumes by age

The volume profile is also important because the largest parts of the market sit in the younger and middle ages, while the oldest vehicles represent much smaller test counts.

Vehicle age	Tests	Pass rate
3	9,410,630	91.39
4	9,964,140	89.33
5	10,166,594	87.08
6	10,130,703	84.6
7	9,701,249	81.89
8	8,878,989	78.9
9	8,006,132	75.87
10	7,321,317	73.09

The highest test count in the table is age 5 with 10,166,594. Age 6 is close behind at 10,130,703. From there, counts trend downward with age: 9,701,249 at age 7, 8,878,989 at age 8, 8,006,132 at age 9, and 7,321,317 at age 10.

At the far end of the range, the pool is much smaller. Age 20 records 1,240,327 tests, age 24 records 257,630, age 27 records 96,348, and age 30 records 62,388. So while the rebound in pass rates at older ages is real within this dataset, it occurs in a much narrower slice of the tested fleet.

What this means for interpreting MOT age effects

The findings support a straightforward reading: vehicle age is strongly associated with lower MOT pass rates through the first half of the observed range. A 3-year-old vehicle posts 91.39, while a 10-year-old vehicle posts 73.09 and a 15-year-old vehicle posts 63.83.

But the relationship is not a simple one-way deterioration all the way to age 30. Instead, the curve has 3 phases visible in the data: a sharp decline from age 3 into the early teens, a low plateau around ages 15 through 20, and then a gradual recovery from age 19 through age 30.

For readers asking, in effect, how MOT pass rates change with age in the UK, this dataset gives a direct answer. The pass rate decays materially from age 3 onward, reaches its lowest point at age 18 with 62.27, and then rises to 70.14 by age 30.

Limitations

This is an age-based pass-rate dataset, not a full MOT market study. It does not provide failure reasons, make or model splits, fuel type, mileage, region, or owner behavior. It also does not identify whether the figures refer to first tests only or all recorded tests within the source system.

The findings also do not include any price information. Questions such as how much an MOT should cost in the UK, average MOT cost in the UK, UK MOT cost in 2023, UK MOT cost in 2024, or MOT test cost in 2024 cannot be answered here.

Likewise, the document does not address UK driving-test pass rates or “Life in the UK” pass rates. Those are separate topics and are not covered by the age-by-age MOT figures in this file.

Frequently asked questions

Q: How does the UK MOT pass rate change with vehicle age? A: In this dataset, the pass rate is 91.39 at age 3, 81.89 at age 7, 73.09 at age 10, 63.83 at age 15, and 63.03 at age 20. The lowest listed pass rate is 62.27 at age 18, before rising to 70.14 at age 30.

Q: At what age is the MOT pass rate lowest in the findings? A: The lowest pass rate shown is 62.27 at age 18. Age 17 is 62.41 and age 19 is 62.47.

Q: Do very old vehicles always keep getting worse in MOT pass rates? A: No. After 62.27 at age 18, the pass rate rises to 62.47 at age 19, 63.03 at age 20, and 70.14 at age 30.

Q: Which vehicle ages have the most MOT tests in the dataset? A: Age 5 has 10,166,594 tests and age 6 has 10,130,703. Age 4 has 9,964,140 and age 7 has 9,701,249.

Q: How many MOT tests are recorded for age 3 vehicles? A: The dataset lists 9,410,630 tests for age 3 vehicles. Their pass rate is 91.39.

Q: How much does an MOT cost in the UK in 2024? A: This findings document does not include MOT price or fee data for 2024. It only provides pass rates and test counts by vehicle age.