DVSA's MOT inspection manual describes dangerous defects as "a direct and immediate risk to road safety or having an impact on the environment". A vehicle with one fails the test, and GOV.UK warns that driving it can bring a fine of up to £2,500, a driving ban and 3 penalty points. In 2025, 3,389,045 dangerous defects were found on 2,419,495 tests. These 10 were found on the most tests:
Source: CarCostCheck analysis of DVSA anonymised MOT test results and failure items, 2025. Class 4 vehicles, first attempt at each MOT. Download the data (Excel).
| Rank | Dangerous defect | Category | Tests | Share of all tests |
|---|
| 1 | Tread depth: tread depth below requirements of 1.6mm | Tyres | 729,872 | 2.20% |
| 2 | Mechanical brake components > Brake linings and pads > Brake pads: less than 1.5 mm thick | Brakes | 586,632 | 1.77% |
| 3 | Condition: has ply or cords exposed | Tyres | 437,325 | 1.32% |
| 4 | Condition: has a tear, caused by separation or partial failure of its structure | Tyres | 188,702 | 0.57% |
| 5 | Condition: has a bulge, caused by separation or partial failure of its structure | Tyres | 138,009 | 0.42% |
| 6 | Brake performance > Parking brake efficiency (sp) > Rbt (sp): efficiency less than 50% of the required value | Brakes | 86,515 | 0.26% |
| 7 | Mechanical brake components > Brake discs and drums > Brake discs: in such a condition that it is seriously weakened | Brakes | 73,538 | 0.22% |
| 8 | Condition: has a lump, caused by separation or partial failure of its structure | Tyres | 54,421 | 0.16% |
| 9 | Tread depth: tread pattern not visible over the whole tread area when minimum depth required is 1.0mm | Tyres | 34,439 | 0.10% |
| 10 | Stop lamp: all not working | Lamps, reflectors and electrical | 31,975 | 0.10% |
The 10 postcode areas where MOT tests found dangerous defects most often in 2025, and the 10 where they found them least often, out of 118. Rates are adjusted for vehicle age; the national rate is 7.29%. The area is where the test centre is, not where the vehicle is kept.
Source: CarCostCheck analysis of DVSA anonymised MOT test results and failure items, 2025. Class 4 vehicles, first attempt at each MOT. Age-adjusted: what the rate would be if the area's vehicles had the national age mix. Download the data (Excel).
| Rank | Postcode area | Tests with a dangerous defect (age-adjusted) | Raw rate | Tests |
|---|
| 1 | Dundee (DD) | 10.32% | 9.61% | 136,142 |
| 2 | Motherwell (ML) | 10.32% | 9.22% | 164,951 |
| 3 | Blackpool (FY) | 10.23% | 10.37% | 141,280 |
| 4 | Cardiff (CF) | 10.08% | 10.04% | 539,734 |
| 5 | Kirkcaldy, Fife (KY) | 9.81% | 9.38% | 186,846 |
| 6 | Sunderland (SR) | 9.74% | 9.40% | 110,602 |
| 7 | Plymouth (PL) | 9.59% | 10.19% | 339,364 |
| 8 | Shetland (ZE) | 9.56% | 8.67% | 12,371 |
| 9 | Truro (TR) | 9.30% | 9.86% | 203,226 |
| 10 | Paisley (PA) | 9.28% | 8.49% | 152,348 |
The 10 areas with the lowest rates:
Source: CarCostCheck analysis of DVSA anonymised MOT test results and failure items, 2025. Class 4 vehicles, first attempt at each MOT. Download the data (Excel).
| Rank | Postcode area | Tests with a dangerous defect (age-adjusted) | Raw rate | Tests |
|---|
| 118 | Romford (RM) | 4.97% | 4.86% | 270,154 |
| 117 | Slough (SL) | 5.02% | 5.07% | 238,810 |
| 116 | Ilford (IG) | 5.11% | 4.91% | 145,784 |
| 115 | London SE (SE) | 5.22% | 5.29% | 260,860 |
| 114 | Kingston upon Thames (KT) | 5.29% | 5.17% | 277,434 |
| 113 | Southall and Uxbridge (UB) | 5.44% | 5.50% | 204,590 |
| 112 | Bromley (BR) | 5.44% | 5.08% | 120,159 |
| 111 | London E (E) | 5.44% | 5.37% | 268,226 |
| 110 | Dartford (DA) | 5.44% | 5.25% | 244,477 |
| 109 | Enfield (EN) | 5.48% | 5.37% | 195,404 |
Tests in Dundee (DD) found a dangerous defect 2.1 times as often as tests in Romford (RM), once vehicle age is allowed for. 5 of the 10 highest areas are in Scotland.
Age-adjusted share of tests failing on each part of the test, highest and lowest areas:
- Brakes: 6.2% of tests nationally. Highest: Dundee (DD) 13.8%, Kirkcaldy, Fife (KY) 12.9%, Aberdeen (AB) 12.7%. Lowest: Romford (RM), 2.9%.
- Suspension: 9.0% of tests nationally. Highest: Kirkcaldy, Fife (KY) 17.6%, Dundee (DD) 17.5%, Aberdeen (AB) 16.1%. Lowest: Southall and Uxbridge (UB), 3.6%.
- Tyres: 6.2% of tests nationally. Highest: Salisbury (SP) 8.7%, Portsmouth (PO) 8.5%, Brighton (BN) 8.3%. Lowest: Romford (RM), 4.3%.
- Lamps and electrical: 10.6% of tests nationally. Highest: Bristol (BS) 13.8%, Exeter (EX) 13.2%, Llandrindod Wells (LD) 13.0%. Lowest: Sutton (SM), 8.5%.
For brakes, suspension and body, chassis and structure, all 10 of the highest areas are in Scotland. The data cannot show why: road salt and wet weather, which speed up corrosion, local roads, how vehicles are used and how strictly testers apply the rules may all play a part. At the other end, all 10 of the lowest areas for brakes, suspension, steering and body, chassis and structure, and for dangerous defects, are in London or on its edge.
Every postcode area
All 118 postcode areas, alphabetically. All rates are adjusted for vehicle age so areas can be compared fairly; the raw figures are in the download.
Source: CarCostCheck analysis of DVSA anonymised MOT test results and failure items, 2025. Class 4 vehicles, first attempt at each MOT. Age-adjusted share of tests. Download the data (Excel).
| Postcode area | Tests | Fail rate | Dangerous defect | Brakes | Suspension | Tyres | Lamps and electrical |
|---|
| Aberdeen (AB) | 254,223 | 36.0% | 8.50% | 12.71% | 16.06% | 6.41% | 10.28% |
| St Albans (AL) | 147,229 | 25.2% | 5.93% | 3.98% | 7.16% | 6.12% | 9.99% |
| Birmingham (B) | 1,038,690 | 23.3% | 5.98% | 4.30% | 6.24% | 4.85% | 9.11% |
| Bath (BA) | 281,050 | 31.4% | 8.44% | 6.90% | 10.44% | 7.46% | 12.53% |
| Blackburn (BB) | 288,425 | 24.2% | 6.96% | 5.91% | 8.88% | 5.12% | 8.76% |
| Bradford (BD) | 295,454 | 25.0% | 7.60% | 7.12% | 9.50% | 5.45% | 8.88% |
| Bournemouth (BH) | 348,639 | 30.0% | 7.39% | 6.28% | 9.00% | 6.93% | 12.06% |
| Bolton (BL) | 254,321 | 26.3% | 7.61% | 6.37% | 9.16% | 5.85% | 10.14% |
| Brighton (BN) | 402,124 | 31.1% | 8.21% | 6.20% | 8.60% | 8.28% | 12.83% |
| Bromley (BR) | 120,159 | 23.1% | 5.44% | 3.56% | 4.66% | 5.30% | 9.51% |
| Bristol (BS) | 575,454 | 33.0% | 8.54% | 6.77% | 10.40% | 7.48% | 13.82% |
| Carlisle (CA) | 197,984 | 29.4% | 7.55% | 7.66% | 10.98% | 5.32% | 10.31% |
| Cambridge (CB) | 235,624 | 27.6% | 6.63% | 4.62% | 7.78% | 7.62% | 10.78% |
| Cardiff (CF) | 539,734 | 31.6% | 10.08% | 8.30% | 10.92% | 7.72% | 12.26% |
| Chester (CH) | 369,836 | 30.6% | 8.00% | 7.35% | 10.62% | 6.62% | 11.03% |
| Chelmsford (CM) | 399,676 | 25.3% | 6.28% | 4.22% | 6.54% | 6.29% | 9.98% |
| Colchester (CO) | 263,541 | 27.2% | 7.38% | 5.35% | 8.26% | 7.20% | 10.45% |
| Croydon (CR) | 225,813 | 22.6% | 5.50% | 3.62% | 4.01% | 4.93% | 10.68% |
| Canterbury (CT) | 256,658 | 27.7% | 7.01% | 5.13% | 8.14% | 7.05% | 10.98% |
| Coventry (CV) | 490,787 | 24.9% | 6.39% | 5.07% | 7.90% | 5.50% | 9.45% |
| Crewe (CW) | 201,472 | 28.6% | 8.18% | 6.41% | 10.23% | 6.51% | 10.01% |
| Dartford (DA) | 244,477 | 23.3% | 5.44% | 3.53% | 4.67% | 4.90% | 10.41% |
| Dundee (DD) | 136,142 | 38.6% | 10.32% | 13.76% | 17.50% | 7.93% | 12.19% |
| Derby (DE) | 458,684 | 25.3% | 6.36% | 5.23% | 8.46% | 5.25% | 9.58% |
| Dumfries (DG) | 77,764 | 26.1% | 6.83% | 7.51% | 11.02% | 5.19% | 8.72% |
| Durham (DH) | 165,399 | 27.4% | 7.35% | 8.05% | 11.11% | 5.03% | 8.87% |
| Darlington (DL) | 192,390 | 31.1% | 7.85% | 8.87% | 12.47% | 5.79% | 10.91% |
| Doncaster (DN) | 433,645 | 27.9% | 6.92% | 6.90% | 9.69% | 5.67% | 9.73% |
| Dorchester (DT) | 130,328 | 29.4% | 7.84% | 6.56% | 9.38% | 7.08% | 11.78% |
| Dudley (DY) | 225,479 | 25.4% | 5.96% | 4.95% | 7.85% | 4.87% | 10.27% |
| London E (E) | 268,226 | 22.8% | 5.44% | 3.16% | 4.10% | 4.61% | 11.11% |
| Edinburgh (EH) | 418,730 | 33.3% | 8.63% | 9.95% | 14.10% | 7.05% | 10.85% |
| Enfield (EN) | 195,404 | 22.3% | 5.48% | 3.25% | 5.04% | 4.94% | 9.95% |
| Exeter (EX) | 374,364 | 32.7% | 8.48% | 7.43% | 11.42% | 7.61% | 13.17% |
| Falkirk (FK) | 143,750 | 34.3% | 8.10% | 10.50% | 15.05% | 6.32% | 11.47% |
| Blackpool (FY) | 141,280 | 31.7% | 10.23% | 8.54% | 10.35% | 8.27% | 12.24% |
| Glasgow (G) | 532,312 | 32.0% | 9.23% | 10.38% | 14.16% | 6.44% | 10.45% |
| Gloucester (GL) | 410,480 | 29.3% | 7.97% | 6.58% | 9.89% | 6.66% | 11.26% |
| Guildford (GU) | 452,871 | 27.6% | 6.59% | 4.69% | 7.55% | 7.06% | 10.83% |
| Harrow (HA) | 200,021 | 21.6% | 5.87% | 3.35% | 3.98% | 5.11% | 9.83% |
| Huddersfield (HD) | 136,701 | 30.9% | 8.32% | 8.18% | 11.90% | 6.24% | 11.90% |
| Harrogate (HG) | 93,386 | 28.6% | 7.27% | 7.33% | 11.72% | 6.20% | 8.95% |
| Hemel Hempstead (HP) | 321,135 | 24.6% | 6.45% | 4.34% | 6.23% | 6.14% | 9.59% |
| Hereford (HR) | 124,342 | 26.5% | 6.82% | 6.21% | 9.33% | 5.55% | 9.50% |
| Outer Hebrides (HS) | 14,821 | 29.3% | 8.05% | 11.85% | 12.65% | 5.85% | 8.86% |
| Hull (HU) | 231,592 | 31.7% | 8.26% | 8.78% | 12.31% | 6.77% | 10.96% |
| Halifax (HX) | 83,006 | 29.4% | 7.85% | 7.72% | 10.80% | 5.95% | 11.50% |
| Ilford (IG) | 145,784 | 21.2% | 5.11% | 2.95% | 4.00% | 4.64% | 9.49% |
| Ipswich (IP) | 395,402 | 27.5% | 6.49% | 5.39% | 8.63% | 7.20% | 10.72% |
| Inverness (IV) | 143,005 | 31.5% | 6.73% | 10.88% | 13.80% | 4.62% | 9.65% |
| Kilmarnock (KA) | 178,062 | 32.8% | 8.93% | 11.20% | 15.16% | 6.12% | 10.08% |
| Kingston upon Thames (KT) | 277,434 | 22.1% | 5.29% | 3.55% | 4.81% | 5.10% | 9.25% |
| Kirkwall (KW) | 27,954 | 29.1% | 7.52% | 10.18% | 10.88% | 5.22% | 9.62% |
| Kirkcaldy, Fife (KY) | 186,846 | 38.6% | 9.81% | 12.90% | 17.56% | 8.10% | 12.55% |
| Liverpool (L) | 363,242 | 26.8% | 7.57% | 5.89% | 8.10% | 5.87% | 10.88% |
| Lancaster (LA) | 180,333 | 28.8% | 8.50% | 7.19% | 10.06% | 6.35% | 10.56% |
| Llandrindod Wells (LD) | 28,363 | 32.4% | 8.47% | 7.52% | 12.11% | 6.81% | 12.99% |
| Leicester (LE) | 588,996 | 25.2% | 6.76% | 5.38% | 7.77% | 5.49% | 9.71% |
| Llandudno (LL) | 317,392 | 28.2% | 7.85% | 7.41% | 10.22% | 6.10% | 9.98% |
| Lincoln (LN) | 188,482 | 32.2% | 7.69% | 7.90% | 12.36% | 6.90% | 11.69% |
| Leeds (LS) | 373,028 | 28.7% | 8.37% | 7.97% | 10.88% | 6.62% | 9.98% |
| Luton (LU) | 219,134 | 23.9% | 6.21% | 3.96% | 5.41% | 5.65% | 9.67% |
| Manchester (M) | 498,510 | 26.2% | 8.05% | 6.19% | 8.23% | 5.91% | 10.45% |
| Medway, Rochester (ME) | 355,113 | 25.2% | 5.95% | 4.17% | 6.38% | 5.64% | 10.73% |
| Milton Keynes (MK) | 349,905 | 26.0% | 6.91% | 4.83% | 7.60% | 5.92% | 10.43% |
| Motherwell (ML) | 164,951 | 34.3% | 10.32% | 12.10% | 15.48% | 7.61% | 10.80% |
| London N (N) | 224,124 | 22.7% | 5.73% | 3.44% | 4.11% | 5.17% | 10.23% |
| Newcastle upon Tyne (NE) | 556,768 | 28.1% | 7.16% | 7.20% | 10.83% | 5.30% | 9.71% |
| Nottingham (NG) | 615,020 | 28.4% | 7.25% | 6.56% | 10.25% | 6.01% | 10.49% |
| Northampton (NN) | 451,667 | 29.5% | 7.32% | 5.95% | 9.27% | 6.70% | 11.03% |
| Newport (NP) | 290,356 | 30.5% | 8.75% | 7.85% | 11.26% | 6.70% | 11.49% |
| Norwich (NR) | 456,336 | 27.8% | 6.45% | 6.16% | 9.42% | 6.90% | 10.39% |
| London NW (NW) | 222,593 | 23.4% | 5.90% | 3.66% | 4.42% | 5.70% | 11.26% |
| Oldham (OL) | 228,131 | 26.3% | 7.84% | 7.06% | 10.13% | 5.60% | 10.32% |
| Oxford (OX) | 371,977 | 27.4% | 7.01% | 5.22% | 8.26% | 6.31% | 10.66% |
| Paisley (PA) | 152,348 | 34.8% | 9.28% | 11.42% | 15.45% | 6.68% | 11.34% |
| Peterborough (PE) | 617,566 | 26.5% | 6.48% | 5.21% | 8.20% | 5.99% | 9.95% |
| Perth (PH) | 98,519 | 33.9% | 8.35% | 11.12% | 14.80% | 6.18% | 10.47% |
| Plymouth (PL) | 339,364 | 32.5% | 9.59% | 9.00% | 11.91% | 7.60% | 12.40% |
| Portsmouth (PO) | 470,819 | 30.7% | 8.02% | 5.91% | 8.46% | 8.52% | 12.29% |
| Preston (PR) | 305,262 | 27.9% | 8.09% | 6.61% | 9.00% | 6.75% | 10.27% |
| Reading (RG) | 506,660 | 25.1% | 6.08% | 4.39% | 6.95% | 6.38% | 9.56% |
| Redhill (RH) | 346,607 | 25.5% | 6.85% | 4.35% | 6.87% | 6.86% | 10.18% |
| Romford (RM) | 270,154 | 21.3% | 4.97% | 2.88% | 4.32% | 4.33% | 9.56% |
| Sheffield (S) | 748,928 | 24.4% | 6.60% | 5.83% | 8.18% | 5.03% | 9.08% |
| Swansea (SA) | 420,193 | 31.1% | 9.11% | 8.29% | 11.12% | 7.03% | 12.47% |
| London SE (SE) | 260,860 | 24.0% | 5.22% | 3.24% | 4.32% | 5.20% | 10.97% |
| Stevenage (SG) | 243,187 | 26.1% | 6.23% | 4.35% | 6.82% | 6.28% | 10.35% |
| Stockport (SK) | 335,237 | 28.7% | 7.80% | 6.70% | 9.83% | 6.28% | 10.90% |
| Slough (SL) | 238,810 | 21.1% | 5.02% | 3.39% | 4.52% | 4.56% | 8.91% |
| Sutton (SM) | 74,585 | 20.3% | 5.71% | 3.51% | 4.36% | 4.98% | 8.49% |
| Swindon (SN) | 295,929 | 28.5% | 7.29% | 5.83% | 8.92% | 6.70% | 10.83% |
| Southampton (SO) | 406,702 | 28.1% | 7.01% | 5.44% | 7.86% | 7.01% | 11.45% |
| Salisbury (SP) | 158,954 | 32.0% | 8.38% | 6.56% | 10.06% | 8.65% | 12.28% |
| Sunderland (SR) | 110,602 | 32.1% | 9.74% | 10.53% | 13.91% | 6.67% | 9.86% |
| Southend-on-Sea (SS) | 291,372 | 22.9% | 6.04% | 4.00% | 5.86% | 5.48% | 9.22% |
| Stoke-on-Trent (ST) | 369,699 | 29.0% | 7.79% | 7.53% | 11.66% | 6.25% | 9.94% |
| London SW (SW) | 143,569 | 23.8% | 5.64% | 3.87% | 4.59% | 5.91% | 9.95% |
| Shrewsbury (SY) | 225,103 | 27.6% | 6.95% | 6.63% | 9.84% | 5.71% | 10.04% |
| Taunton (TA) | 216,962 | 29.9% | 7.47% | 6.12% | 10.03% | 6.77% | 11.80% |
| Galashiels, Borders (TD) | 63,580 | 30.6% | 7.87% | 9.91% | 12.80% | 5.46% | 10.53% |
| Telford (TF) | 126,213 | 27.4% | 7.03% | 6.65% | 10.37% | 5.63% | 9.57% |
| Tonbridge (TN) | 444,593 | 27.0% | 7.13% | 5.22% | 7.72% | 6.86% | 10.73% |
| Torquay (TQ) | 169,212 | 31.0% | 8.59% | 7.31% | 10.16% | 7.09% | 12.58% |
| Truro (TR) | 203,226 | 32.1% | 9.30% | 9.28% | 12.13% | 7.47% | 12.27% |
| Cleveland, Teesside (TS) | 308,110 | 29.0% | 7.42% | 8.12% | 11.04% | 5.50% | 10.01% |
| Twickenham (TW) | 243,664 | 22.1% | 5.74% | 3.27% | 4.46% | 5.75% | 9.31% |
| Southall and Uxbridge (UB) | 204,590 | 20.5% | 5.44% | 3.24% | 3.64% | 4.51% | 9.48% |
| London W (W) | 89,445 | 23.9% | 5.77% | 3.74% | 4.57% | 6.00% | 10.28% |
| Warrington (WA) | 340,511 | 28.4% | 7.93% | 6.29% | 9.76% | 6.38% | 10.37% |
| Watford (WD) | 131,712 | 28.2% | 7.25% | 5.04% | 7.67% | 7.42% | 11.25% |
| Wakefield (WF) | 294,917 | 26.5% | 8.33% | 6.92% | 9.65% | 6.18% | 9.22% |
| Wigan (WN) | 154,429 | 30.2% | 8.57% | 7.26% | 10.27% | 6.91% | 11.42% |
| Worcester (WR) | 195,980 | 26.5% | 6.98% | 5.36% | 8.37% | 5.98% | 9.99% |
| Walsall (WS) | 238,943 | 28.0% | 7.50% | 5.77% | 9.08% | 6.23% | 10.91% |
| Wolverhampton (WV) | 224,384 | 25.8% | 6.96% | 5.45% | 7.56% | 5.59% | 10.35% |
| York (YO) | 315,714 | 30.2% | 7.45% | 8.52% | 12.35% | 6.18% | 10.06% |
| Shetland (ZE) | 12,371 | 35.3% | 9.56% | 11.69% | 11.61% | 6.85% | 11.85% |
The share of tests with a dangerous defect rises from 3.6% for 2-year-old vehicles, which are mostly at their first MOT, to a peak of 10.3% at 17 years old. Suspension failures rise from 0.6% of tests at 2 years old to 17.6% at 16, and lamp and electrical failures from 2.5% to 21.4% at 19. Tyre failures change much less, staying between 4.7% and 7.4% from 2 to 20 years old.
Source: CarCostCheck analysis of DVSA anonymised MOT test results and failure items, 2025. Class 4 vehicles, first attempt at each MOT. Age in whole years since first use. Download the data (Excel).
| Vehicle age (years) | Fail rate | Dangerous defect | Brakes | Suspension | Tyres | Lamps and electrical |
|---|
| 2 | 11.2% | 3.61% | 1.27% | 0.62% | 4.99% | 2.51% |
| 3 | 12.2% | 3.80% | 1.70% | 0.93% | 4.74% | 2.63% |
| 5 | 15.5% | 5.19% | 2.92% | 1.97% | 5.14% | 3.78% |
| 7 | 20.7% | 6.20% | 4.01% | 4.79% | 5.75% | 5.59% |
| 10 | 30.0% | 7.66% | 6.41% | 9.92% | 7.20% | 10.29% |
| 12 | 35.5% | 8.89% | 7.77% | 13.50% | 6.83% | 14.98% |
| 15 | 41.4% | 10.11% | 9.97% | 17.06% | 7.35% | 19.50% |
| 17 | 42.7% | 10.28% | 11.23% | 17.50% | 7.17% | 20.79% |
| 20 | 42.4% | 9.79% | 12.76% | 16.68% | 6.25% | 21.10% |
| 25 | 36.2% | 7.35% | 11.40% | 12.85% | 3.98% | 16.42% |
DVSA only publishes MOT data by postcode area. To help MPs and councils see where their area stands, we matched each of the 632 Westminster constituencies in Great Britain (2024 boundaries) to the postcode areas it covers, using the ONS National Statistics Postcode Lookup, and estimated each constituency's figures from those areas. Half of all constituencies lie almost entirely (99.7% or more of their postcodes) in a single postcode area. The constituency table is in the Excel workbook and as a CSV.
How to check a car's MOT history before you buy
- Look up the full MOT history. Enter the registration in our free MOT history check to see every test since 2005, with each fail and advisory.
- Look for repeat problems. Brake, tyre and suspension advisories that come back year after year, or advisories that turn into fails, are worth asking the seller about.
- Check what the MOT does not cover. The MOT does not look for outstanding finance, write-offs or a stolen record. Our £4.99 history check covers these, with a one-off payment.
Journalists, researchers and campaigners
You are welcome to use these figures and tables free of charge, with a link to this page as the source (CarCostCheck, carcostcheck.co.uk/blog/mot-failure-reasons-2025).
For figures for a particular area or constituency, or a comment, email hello@carcostcheck.co.uk.
Download everything (Excel workbook with notes), or the tables as CSV files:
- Source: DVSA anonymised MOT test results and failure items for tests carried out between 1 January and 31 December 2025, with DVSA's current defect lookup tables.
- Tests: class 4 vehicles (mainly cars and light vans up to 3,000kg, plus taxis, private hire vehicles and motor caravans), normal tests only (the first attempt at each MOT), with a result of pass, fail or pass after rectification at station (PRS). A PRS counts as a fail, as in DVSA's own initial fail rate. 33,210,951 tests, 9,193,623 fails, the same totals as our 2025 area and brand study.
- Defects: every fail and PRS defect recorded on a failed test, 22,036,332 in all, grouped into DVSA's top-level defect categories. As in DVSA's own method, a test counts once in a category however many defects it had there. Advisories and minor defects are not counted.
- Dangerous and major: the defect category DVSA gives each defect. DVSA's dangerous marker agrees with it for all 3,389,045 dangerous defects.
- Areas: the postcode area of the test centre. The area tables use the 33,202,115 tests with a known vehicle age and postcode area, so the test counts and fail rates match our 2025 area study exactly. DVSA merges areas with fewer than five active test centres under the code XX (2,165 tests), which is left out.
- Age adjustment: for each area and measure, the expected number is the sum across every age (0 to 60 years) of the area's tests at that age multiplied by the national rate at that age. The age-adjusted rate is the observed number divided by the expected number, multiplied by the national rate.
- Constituencies: live residential-type postcodes in the ONS National Statistics Postcode Lookup (August 2026). Each constituency's figures blend those of the postcode areas it covers, weighted by its share of postcodes in each. These are estimates.
- Checks: for every quarter of 2025, the share of tests failing on each defect category is within 0.02 percentage points of DVSA's own published figures (table DVSA/MOT/03), and the share with a dangerous defect is within 0.01 points. Three areas were recounted separately from the raw files and matched exactly.
- Limitations: differences between areas can reflect roads, weather, how vehicles are used and how strictly testers apply the rules, as well as maintenance. The figures are adjusted for vehicle age only, not mileage or the makes and models tested. Class 4 includes light vans.
Source: CarCostCheck analysis of the DVSA anonymised MOT tests and results dataset, 2025, and the ONS National Statistics Postcode Lookup. Contains public sector information licensed under the Open Government Licence v3.0. DVSA's own figures by defect category are in its MOT testing data for Great Britain.