A registration number shows the reading, age explains it

In brief

• The free record shows one odometer reading: the one taken at the most recent inspection. The full series of readings sits in the paid history section.
• A failure rate says more about age than about condition. Of cars first registered in 2021, 8.2% failed; of 2006 cars, 43.1%.
• When the last periodic inspection and the last passed periodic inspection fall on different dates, the previous visit ended in a failure.

The free record tells you more than the listing

The vehicle information service run by the Finnish Transport and Communications Agency (Traficom) gives three groups of data free of charge, either by registration number, the one on the plate, or by vehicle identification number: technical data, inspection data and tax data. The names of the owner and the holder, and the vehicle's history data, are chargeable. That split decides what you can see before you contact the seller, and the free side goes surprisingly far. The record also shows the vehicle's status and any restrictions, so it says outright if a periodic inspection is unperformed or unpassed.

The inspection data has four lines. The last periodic inspection tells you when the car was most recently on the lane, and the last passed periodic inspection tells you when it most recently came through. The next inspection window tells you by when the next visit has to happen. The fourth line is the latest odometer reading recorded at an inspection, with its date. The first three tell you when; only the fourth tells you how much.

The vehicle's status is one of the first lines in the record. It shows whether the car is registered for road use or has been taken off the road, and the latter is worth knowing before you agree a test drive: a car taken off the road is not in traffic until it is declared back into use. Listings rarely mention it, because it says nothing about the car itself, only about its administrative standing.

Some of the same data is on paper in the technical part of the registration certificate, which also shows the next inspection date, but you cannot see the paper before you see the car. A registration number works in advance. It is in the listing either written out or visible in a photo, and if it is in neither, you can ask the seller for it before agreeing a viewing.

None of the figures is good or bad on its own. The odometer reading, the failure rate and the inspection interval all depend on the year the car was first taken into use, so the benchmark is other cars of the same year rather than the market as a whole. Three years are enough to show the difference. Cars first registered in 2021, in 2013 and in 2006 are three different worlds, even when they sit side by side on the same page of listings.

Only the most recent reading shows up

The odometer reading is taken at every periodic inspection, and it is the only figure about the car that the seller did not write. The free record shows one point of it, the most recent. The full series sits in the inspection history, which lists the date, the type of inspection, the decision and the reading for every visit, and that belongs to the paid section. The difference is large: one point tells you where the car is now, the series tells you how it got there.

That single point is still worth reading, because it has a benchmark. For cars first registered in 2021 the median reading taken at inspection is 66,000 km, for 2013 cars it is 190,000 km and for 2006 cars 253,000 km. Across all inspected cars in Finland the median is 187,000 km, which puts the middle car close to the 2013 year group.

The deviation from the benchmark is what to look at. If a car first registered in 2013 shows clearly less than the median for its year, there is a reason: it has been a second car, it has stood off the road for a long time, or the instrument cluster has been replaced. None of those is a fault, but each is a question worth asking before the sale. The same applies the other way round, and then the answer is usually work mileage.

It is also worth comparing the reading with what the car itself shows. Pedal rubbers, the steering wheel surface, the side bolster of the driver's seat and the gear knob wear with use and follow actual driving rather than the number on the dial. If the recorded reading and the surfaces of the car tell different stories, the question goes to the seller. The trick is old, but it still works, because wear is physics rather than a record.

The value of the series is that it is a timeline. In the inspection history the readings grow from one visit to the next, and if any reading is lower than the one before it, something has happened: the cluster has been changed, the figure was entered wrongly, or it has been tampered with. A single point never reveals that, because there is nothing to compare it against. The length of the series grows with the car's age: a nearly new car has one line, a fifteen-year-old car has more than ten.

Of the three explanations only one is the buyer's problem, and without the whole series they cannot tell which.

An odometer reading that has not been taken at an inspection is a seller's claim, not an observation.

A failure rate measures age before condition

There were 1,672,937 periodic inspections, and 26.9% of them ended in a failure. That figure describes no single car, because failure follows age more closely than anything else. Of the 2021 year group 8.2% failed, of the 2013 group 23.6% and of the 2006 group 43.1%. A gap of more than thirty percentage points is not a gap in build quality but in fifteen years.

A failure rate is not read without an odometer reading beside it. The year group that fails most often is also the one with the highest median reading: for 2006 cars both are the highest of the three. When two measures move in the same direction they are measuring the same thing, wear, and wear accrues in kilometres as much as in years.

Age still does not explain everything, and you can see that where the order reverses. Of the 2020 year group 11.4% failed and of the year before it 10.7%, so the younger group did worse. The difference is small, and the younger group's inspections are a fraction of the older group's. Small groups swing, and that is worth remembering whenever two adjacent years are set against each other.

For a buyer the percentage is a probability rather than a forecast. It says how many cars of the same age did not pass, not what will happen to this one. The practical meaning is money: the older the year group, the greater the chance that the next inspection brings a repair bill with it, and that bill belongs in the purchase price just as much as tyres do. The inspection window is in the record, so its timing can be taken into account before an offer is made. A car whose window closes in a month is a different purchase from one that has just come through, even when both are from the same year and cost the same.

One simple way of reading follows from this. The free record carries two dates, the last periodic inspection and the last passed periodic inspection. If they are the same day, the previous visit went through first time. If they are not, the car was failed and then repaired, and it is worth asking what failed it. This is the only direct clue to failure history in the free record.

Fault entries pile up in the suspension and the brakes

When the reason for a failure becomes clear, it lands almost always in the same places. Axles, wheels and suspension collected 308,940 faults and braking systems 217,030. These are counts of faults rather than of cars, because one car can carry several entries in the same category. The order stays the same whichever year group you look at, and it shows where the money goes in a used car. Preparing for an inspection is covered separately in an article on the real reasons cars fail.

Behind the leaders come environmental nuisance, chassis and body, and steering equipment, and they all share one feature. The fault is in a place you cannot see without a ramp or a measurement. Listing photos are taken around the car at eye height, and none of them looks underneath it. That is not the seller's doing but a property of the camera angle, and it is exactly why the register's entries are different information for a buyer than the photos are.

The order of fault categories is worth keeping in mind on the test drive too. Once you know that most entries accrue in axles, wheels, suspension and brakes, you listen for different things: knocks on uneven surfaces, play in the steering, and whether the car brakes straight. The register tells you where to concentrate, and the ear does the rest.

A fault should be kept apart from a repair recommendation. Altogether 783,266 faults and 1,002,794 repair recommendations were recorded, so there were more recommendations than actual faults. A repair recommendation is a note about a defect that did not prevent the car from passing, and for a buyer it is useful precisely for that reason: it says what the car is heading towards. Recommendations do not appear in the vehicle information service, so they have to be requested from the seller in the inspection certificate.

The gap between the two figures also explains why a failure rate is not the whole truth. A large share of the defects found at inspection does not show in that figure at all, because they did not prevent the car from passing.

An older car leaves a longer trail

The number of inspection entries is not random but follows the inspection interval. According to Traficom a passenger car is inspected for the first time no later than four years after the date it was taken into use, then no later than every two years, and once more than ten years have passed since it was taken into use, the inspection is annual. So a 2021 car has one entry behind it, a 2013 car has accumulated six or seven, and a 2006 car more than ten.

The difference also shows in what the paid history gives you. It contains the inspection history with its readings, the ownership history with the length of each ownership, the insurance history and the usage history, which shows off-road periods with their reasons and dates. For a young car the series are short, and the paid record says little more than the free one. In a fifteen-year-old car the series are long, and that is exactly where the money is worth spending.

Off-road periods are a chapter of their own. A car that has stood for years collects fewer inspection entries and fewer kilometres than its age suggests, and the odometer reading then looks better than the car's condition is. Standing still is not a fault, but it moves wear from time to something else: seals, brakes and tyres age in a garage too. The periods appear in the paid history with their reasons.

The ownership history is another place where a long series says more than a single line. It shows every owner and how long the car stayed with each. Two short ownerships in a row prove nothing on their own, but together with a recent failure they are a pattern worth asking about. The names are in the paid section, though what interests a buyer is the length of the ownerships rather than who owned the car.

There is one point in reading the inspection window that often goes wrong. According to Traficom the next date does not move if the inspection is carried out on the last day of the window or within the 30 days before it, so an inspection done in good time does not shorten the car's interval.

An unpaid tax can stop the car

Tax data belongs to the free record, and it is worth looking at before money is discussed. According to Traficom a vehicle may not be used until all overdue taxes and their interest have been paid and any other restrictions causing a use ban have been lifted. That is a hard condition, and it applies to the car rather than to the listing. The tax data in the record has four points a buyer should read.

• The daily amount of the basic vehicle tax and the annual total.
• Whether the car has open vehicle taxes or additional taxes.
• Restrictions, such as a note that a periodic inspection is unperformed or unpassed.
• The fuel type and emissions the tax amount is based on.

For a buyer this is the only point in the record that can stop the car being used straight after the sale. If a vehicle has more than one unpaid tax, each of them has to be paid with its own reference, and with payment methods other than Traficom's own e-service the payment can take several banking days to register. Lifting a use ban is therefore not the same thing as a payment receipt, and it is worth allowing time for it before the car is collected.

The annual cost is a second reason to look at this section. The yearly vehicle tax starts running as soon as ownership changes, and it varies with the car's fuel type and emissions more than many expect. Two cars at the same price can differ clearly in their annual cost, and the difference is visible in the record before either has been seen.

Car tax and fuel fees are not shown in the service, so the record is not exhaustive on taxes. It does answer the question a buyer has at the moment of sale: can the car be driven away.

Technical data tells you what the car should have

The free record also contains the full technical description, and the listing text can be read against it line by line. If a listing promises equipment or a towing capacity that the technical part does not recognise, it is either an error or the data of an entirely different car.

• Fuel type, maximum net engine power and top speed.
• Emission level and emission class, and the stated consumption figures.
• Body type and number of seats.
• Dimensions and mass data by axle.
• Axle data, braking system and safety equipment by position.
• Type-approved tyres and rims by axle.

Of those fields the fuel type decides the most. It determines the structure of the vehicle tax, and it also tells you how ordinary a car you are buying. Of cars registered for road use 62.3% run on petrol and 23.0% on diesel, while electric cars account for 7.0% and plug-in hybrids for 6.9%. What you meet most often is therefore a petrol car, and its background data is also the easiest to check.

The mass data shows the kerb weight, the maximum permitted laden mass and the trailer masses with and without brakes. These are exactly the figures that listings repeat from memory and often get wrong. If the car is meant to tow a trailer or a caravan, the technical part is the only place to get the figure right before the sale, and it is in the free record.

Tyre data is a small but practical section. The record gives the type-approved tyre size by axle with its load index and speed rating, and against that you can check whether the tyres on the car are what they should be. The wrong size is not always dangerous, but it is always a question, and tyres are one of the first costs in a used car.

Differences between model series are not a ranking of condition

Failure rates for individual models also turn up easily, and they should be handled with care. Failure rates for individual model series land between 2.2% and 56.7%, but that range does not measure how well the models last. The series differ from each other in age and mileage distribution: at the low end the median reading is typically under a hundred thousand kilometres, while at the high end it is usually two or three times that. A percentage without an odometer reading beside it is not a comparable figure, and the comparison is only meaningful within the same year of first registration.

You could conclude from this that a registration number is of no use to a buyer at all: if every figure is explained by age, it says nothing about an individual car. The conclusion collapses as soon as the benchmark is set correctly. The number does not tell you whether a car is good, but it does tell you where in its own year group the car sits, and that deviation from the year group is exactly the signal a listing lacks entirely.

Comparison is also made harder by the fact that the series differ in size. In a small series a handful of failures moves the percentage more than in a large one, and the extremes therefore tend to be occupied by small groups. The same effect shows between year groups, and it is why the number of inspections should always be read alongside the percentage.

The same caution applies to the figures for an individual car. The register's entries say what has been done to the car and when, not how it has been looked after between those visits. Oil changes, cam belts and repairs are not in the register at all, and those are what decide how long the car lasts. A check narrows down the bad options but does not pick a good one: that choice is made on the service book and the test drive.

The year of first registration is therefore a benchmark rather than background, and it is on the first lines of the record, next to the date the car was taken into use.

The same reading means different things in different years

The three figures are read together, and always in the same order: the year of first registration first, the odometer reading second, the inspection dates third. Take a reading of 190,000 km as an example. In a 2013 car it lands on the median for its year and says nothing in particular. In a 2021 car the same reading is nearly three times its year group. In a 2006 car it falls clearly below its year group, and then the question is where the car has been.

The inspection dates sharpen the picture. If a 2006 car's last periodic inspection and last passed inspection are on different dates, the car has just been repaired through, and that often explains why it is on sale now. If the dates are the same and the reading is below its year group, this is a little-driven old car that went through first time. Those two cars can cost the same, but they are not in the same condition.

Of the three year groups it is the middle one where judgements go wrong most often. A 2013 car still looks modern in listing photos and its price has already fallen to something tempting, but its reading is close to the national median and failures already occur in almost a quarter of visits. It is the car where a register check yields the most, because the gap between impression and measurement is widest there.

A third possibility is that the listing has no registration number at all. That is information too, because without it none of the above can be checked. Asking for the number before a viewing is not a sign of distrust but the same thing as asking for the model year: it is public information the seller knows by heart.

Do the check before you see the car

A check by registration number takes a couple of minutes and saves pointless journeys. Before you book a time you know the car's year of first registration, its latest recorded odometer reading, its next inspection window, the state of its taxes and whether the previous inspection went through first time. In the listing those are at best written by the seller, and at worst not there at all.

• Look at the year of first registration first and only then at the odometer reading.
• Compare the reading with the median for its own year, not with the figure for the whole market.
• Check whether the last periodic inspection and the last passed inspection fall on the same day.
• Look in the tax data for open taxes or entries that restrict use.
• Ask the seller for the inspection certificate, because repair recommendations do not appear in the vehicle information service.

If something does not match, it does not mean the car is bad. It means the listing has a point on which the seller either has an explanation or does not. Either answer moves things forward, and both come faster than driving out to look.

The value of the check is not that it finds a fault. Most of the time it finds nothing, and even then it has done its job: the listing's figures match the register, and at the car you can concentrate on looking at the car rather than doing arithmetic. A purchase decision is easier when there is one open question fewer, and in this case that one is precisely the one anybody can check without any expertise.

None of this replaces a test drive or a look from a ramp, and the figures say nothing about how the car drives. They say what has been done to the car and what company it keeps, and that is enough to weed out the ones where the listing photos and the register's entries tell different stories. The rest becomes clear on the spot.

See cars from the 2016 model year and older