Pass rate
90.5%
Above average — 0.7 pts behind the 91.2% that cars this age and mileage manage.
Across 2,333 recorded tests.
Typical repair bill £35–£78
2021 SEAT Mii MOT pass rate
- 2021
- typical 19,592 mi
Most common fault
Tyres
53.6% of faults · 19.8% nationally
mostly tread below the limit, cuts and sidewall bulges.
Which year to buy
- Best 2019 92.4% pass
- Avoid 2012 81.6% pass
Across the 10 years on record, a spread of 10.8 points. See every year →
- First-attempt pass
- 89.6%
- Typical mileage
- 20k mi
The 2021 SEAT Mii MOT pass rate is 90.5% of its MOT tests — about what its age and mileage predict. Tyres is the biggest single reason it fails, at 53.6% of what testers record.
Check your postcode
MOT pass rates are national — type your postcode to see how SEAT Mii does in your corner of the country.
Expert verdict
Tyres: 2.7× the national share
Tyres make up 53.6% of everything recorded on the 2021 SEAT Mii, against 19.8% nationally — 33.8 points above. Check all four tyres yourself, including the inner shoulders, and look at the date stamp — a tyre can pass on tread and still be six years old.
- When it fails, it costs. Only 21% of this model’s typical repairs come in under £30 in parts — the failures here tend to be the kind that need a garage rather than a bulb.
Written from this page's own figures: fault shares against the national composition, the like-for-like pass rate, and the priced repair list. How these are worked out
Watching a SEAT Mii? Get an email when these numbers change .
How does the 2021 SEAT Mii compare?
Cars of this age and mileage average 91.2%, so this figure is 0.7 points behind what its age and mileage predict. On a first attempt, before any retests, the figure drops to 89.6%. The median 2021 SEAT Mii in this dataset had covered 19,592 mi.
Pass rates also shift with the test month: tests recorded October–March passed 90.5% of the time, April–September 90.5%.
The single most recorded failure item is "Has a bulge, caused by separation or partial failure of its structure", noted on 3.34% of tests.
- 2,333 recorded tests behind this page.
- 90.5% overall pass rate, 89.6% on a first attempt.
- Across every year of the SEAT Mii, the average is 85.4% — best year 2019 (92.4%), worst 2012 (81.6%).
Figures count every completed test on this vehicle-year in the dataset, including retests. See methodology for the exact definition.
This page's data
- Tests analysed
- 2,333
- Typical mileage (median)
- 19,592 mi
- Make and model
- SEAT Mii
- Updated
- 2026-11-05
Source: DVSA anonymised MOT test data (2023–2025), OGL v3.0.
Top part to budget for
Tyres
Usually a DIY or independent-garage job.
Does mileage affect the Mii MOT pass rate?
Pass rate by odometer reading. Bar lengths start at 72% so small gaps stay visible.
Regional pass rates for the Mii
| Region | Tests | Pass rate |
|---|---|---|
| South East | 498 | 89.2% |
| East Midlands | 307 | 84.0% |
| East of England | 289 | 91.7% |
| South West | 266 | 91.7% |
| Scotland | 182 | 88.5% |
| North West | 179 | 96.1% |
| Yorkshire | 179 | 92.7% |
| West Midlands | 164 | 92.1% |
| North East | 122 | 94.3% |
| Wales | 102 | 90.2% |
| London | 45 | 95.6% |
Regions come from the postcode area recorded at the test station. Areas on region borders are assigned to the region with the majority of their population.
What fails a 2021 Mii
Everything a tester recorded on this vehicle, grouped into the inspection sections that produced it. The notch on each bar is the national share, so you can see at a glance whether this car is unusual or just ordinary.
A test can record several items, so these percentages do not add up to 100%. The exact strings, with prices, are in the full DVSA record at the bottom of this page.
Before your test
Three checks worth doing on a 2021 Mii
These are not generic tips — they are the faults recorded most often on this exact model, rewritten as things you can check yourself. All three take about ten minutes and cost nothing.
-
Check the wipers and washers 1.0% of tests
“wipers blade defective”
Run the wipers with the screen wet: they should clear it in one sweep without smearing or juddering. Top the washer bottle up and check both jets hit the screen.
-
Check the suspension joints 0.8% of tests
“linkage ball joints ball joint excessively worn”
With the car parked on level ground, rock the top of each front wheel in and out while someone watches the suspension arm. Clunks, or rubber boots split and greasy, are what testers record here.
-
Check the lights 0.6% of tests
“headlamp aim too low”
Switch everything on and walk round the car: both headlamps on dip and main, every indicator, both brake lights, reverse, fog and the two number-plate lamps. A bulb is a few pounds and a five-minute job.
Shares are the proportion of tests on this vehicle that recorded the item, so they overlap: one test can record several.
What it costs to get a 2021 Mii through its MOT
Across the 10 items that are recorded most often on this model, the average repair comes to £35–£78 — and 21% of those repairs are parts that cost under £30.
- Average repair across the 10 common items
- £35–£78
- Cheapest common item: washers provides insufficient washer liquid
- £5–£15
- Dearest common item: windscreen damaged
- £80–£200
- Common items a careful owner can do at home
- 80%
- Repairs that still cost under £30
- 21%
Estimates from typical UK parts prices, weighted by how often each item appears in 2,333 MOT tests on this vehicle. They exclude diagnostics, retest fees and garage labour where the part is a DIY fit, and they are not figures from the DVSA dataset. Older and higher-mileage examples cost more than the average. How these estimates are built → · All MOT repair costs → · Cheapest cars to put through a test →
Every year of the Mii, side by side
10 model years on record, from 2012 to 2021. Across them the pass rate runs from 81.6% to 92.4% — a spread of 10.8 points. The bar under each year is the item that failed it most often.
- 2012 81.6% srs malfunction indicator lamp…
- 2013 82.4% service brake performance…
- 2014 84.7% service brake performance…
- 2015 84.9% service brake performance…
- 2016 85.0% pins and bushes pin or bush…
- 2017 87.9% pins and bushes pin or bush…
- 2018 89.9% wipers does not clear the…
- 2019 92.4% headlamp aim too low
- 2020 91.0% has a bulge, caused by separation…
- 2021 90.5%has a bulge, caused by separation…
Colour is the pass rate on a fixed scale, so a block means the same thing on any model. Each year links to its own page with the full fault breakdown.
Compare the 2021 SEAT Mii with another year
The raw pass rate mostly measures age. The year comparison adds the like-for-like figure, the mileage bands and the repair bill.
Other 2021 cars with a similar record
- Vauxhall Corsa Griffin 90.5%
- Mitsubishi L200 90.5%
- Kia Picanto GT-Line 90.5%
- Kia Sportage 90.4%
- Vauxhall Mokka 90.6%
- BMW 218I 90.6%
Closest pass rates among 2021 cars with at least 2,000 tests, so a small sample cannot flatter itself into the list. See the full rankings: best and worst MOT pass rates.
The full DVSA record for the 2021 SEAT Mii 10 failure items · 6 advisories · 10 inspection categories · mileage brackets · all of it in the page, none of it above the fold
Every inspection category
Shares of the 1,224 individual items recorded on this vehicle, and the same share across all cars nationally. A single test can record several items, so a row is not a percentage of tests.
| Category | Items | This car | Nationally | Difference |
|---|---|---|---|---|
| Tyres | 658 | 53.60% | 19.76% | +33.84 |
| Brakes | 133 | 10.80% | 20.89% | −10.09 |
| Non-component advisories | 118 | 9.60% | 4.18% | +5.42 |
| Suspension | 117 | 9.50% | 20.98% | −11.48 |
| Visibility | 82 | 6.70% | 4.97% | +1.73 |
| Lamps, reflectors and electrical equipment | 80 | 6.50% | 12.21% | −5.71 |
| Identification of the vehicle | 21 | 1.70% | 1.76% | −0.06 |
| Seat belts and supplementary restraint systems | 6 | 0.50% | 0.82% | −0.32 |
| Road Wheels | 5 | 0.40% | 0.75% | −0.35 |
| Body, chassis, structure | 4 | 0.30% | 5.57% | −5.27 |
The exact failure items, in the tester's words
| Recorded item | Severity | Tests | Est. cost |
|---|---|---|---|
| Has a bulge, caused by separation or partial failure of its structure Tyres | Major | 3.3% | £45–95 |
| Has a cut in excess of the requirements deep enough to reach the ply or cords Tyres | Major | 1.1% | £45–95 |
| Wipers blade defective Visibility | Minor | 0.99% | £8–22 |
| Linkage ball joints ball joint excessively worn Suspension | Major | 0.81% | £18–45 |
| Headlamp aim too low Lamps, reflectors and electrical equipment | Rectified | 0.64% | £30–80 |
| Windscreen damaged but not adversely affecting driver's view Visibility | Minor | 0.60% | £80–200 |
| Washers provides insufficient washer liquid Visibility | Rectified | 0.56% | £5–15 |
| Has a lump, caused by separation or partial failure of its structure Tyres | Major | 0.47% | £45–95 |
| Ball joint excessively worn Suspension | Major | 0.43% | £18–45 |
| Registration plate lamp(s) inoperative in the case of a single lamp or all lamps Lamps, reflectors and electrical equipment | Rectified | 0.39% | £5–20 |
Severity is as recorded: Major and Dangerous fail the test outright; Minor and Advisory do not. Costs are estimates from typical UK parts prices — see how they are built.
What testers noted without failing the car
Advisories are the early warnings — the same parts a year or two before they fail. Reading them is how you tell a car that has been maintained from one that has been patched.
| Recorded item | Severity | Tests | Est. cost |
|---|---|---|---|
| Tread depth below requirements of 1.6mm Tyres | Advisory | 9.2% | £45–95 |
| Has a tear, caused by separation or partial failure of its structure Tyres | Advisory | 8.7% | £45–95 |
| Brake discs in such a condition that it is seriously weakened Brakes | Advisory | 3.0% | £45–110 |
| Non-component advisories Nail in tyre Non-component advisories | Advisory | 2.3% | £45–95 |
| Has a cut in excess of the requirements deep enough to reach the ply or cords Tyres | Advisory | 1.7% | £45–95 |
| Non-component advisories Child Seat fitted not allowing full inspection of adult belt Non-component advisories | Advisory | 1.3% | £20–80 |
Pass rate by mileage
| Mileage | Tests | Pass rate | Median odometer |
|---|---|---|---|
| 0-30k | 1,883 | 91.3% | 17,145 mi |
| 30-60k | 427 | 87.4% | 38,072 mi |
| 60-90k | 15 | 80.0% | 69,052 mi |
Source: 2,333 recorded tests on this vehicle-year. Every row above is recomputed from the same DVSA extract as the rest of the page — see the methodology.
2021 Mii MOT questions
What is the MOT pass rate for a 2021 SEAT Mii?
90.5% of the 2,333 2021 SEAT Mii tests in this dataset passed, against a national average of 91.2% for cars first used in 2021. First-attempt pass rate: 89.6%.
What are the most common MOT failures on a 2021 SEAT Mii?
The three most recorded items are has a bulge, caused by separation or partial failure of its structure (3.34%), has a cut in excess of the requirements deep enough to reach the ply or cords (1.11%), wipers blade defective (0.99%). Percentages are the share of tests on this vehicle that recorded the item.
Does mileage affect the 2021 SEAT Mii MOT pass rate?
Yes. Cars under 30,000 miles passed 91.3% of the time, falling to 80.0% for those over 120,000 miles. The median 2021 SEAT Mii in this dataset had covered 19,592 mi.
Does the season affect the 2021 SEAT Mii MOT pass rate?
Tests recorded in the winter months (October–March) passed 90.5% of the time; summer months (April–September) passed 90.5%. Brakes, tyres and lights are tested harder in bad weather, but the difference is small on most models.