There is no single speed camera tolerance, and in the UK the figure people quote is police guidance, not a rule. Two different things get that name. A measurement margin is subtracted from the camera reading before anything is charged; the Netherlands, Germany and France publish theirs. An enforcement threshold is the speed from which the police normally act; in the UK it comes from National Police Chiefs' Council (NPCC) guidance, which starts a fixed penalty at 35 mph in a 30 limit and says forces may prosecute below it. This guide covers the UK, the Netherlands, Germany and France, as read on 17 October 2026. It does not cover Belgium, where the official pages read give no correction figure, or the United States.
What speed camera tolerance means
A margin exists because every measuring device has an error. The Dutch prosecution service (OM) says the police take a few km/h off the reading so that they can guarantee with 100% certainty that someone was speeding. That protects the driver from device error; it does not permit anything. A threshold is a policy choice: an authority acts only from a set speed above the limit, even when the corrected speed is already over it. Neither is a buffer you can count on: the NPCC guidance says so plainly, and Service-Public lists a French fine for an excess of under 5 km/h.
United Kingdom: thresholds, not a margin
Section 5.4 of the NPCC guidance (2025, version 2.0) says type approved devices must give a positive error no larger than 2 mph, or 3% above 66 mph, and adds that "it is therefore possible to enforce against these tolerances". Section 5.6 then gives a table; the columns below are copied from it.
| Speed limit | Device tolerance | Fixed penalty from |
|---|---|---|
| 20 mph | 22 mph | 24 mph |
| 30 mph | 32 mph | 35 mph |
| 40 mph | 42 mph | 46 mph |
| 50 mph | 52 mph | 57 mph |
| 60 mph | 62 mph | 68 mph |
| 70 mph | 73 mph | 79 mph |
Every "fixed penalty from" figure equals the limit plus 10% plus 2 mph. That is our arithmetic: the guidance never states a formula. What it does say is that publishing thresholds "has also resulted in the creation of a pseudo speed limit", that nothing in it restricts forces from prosecuting for speeds below the thresholds, and that such decisions are taken case by case.
The guidance aims at "general consistency across UK policing", but every Chief Constable is free to set local policy (sections 1.1 and 1.3), and none of the pages read shows how Police Scotland or the Police Service of Northern Ireland apply the table. GOV.UK puts the minimum penalty at a £100 fine and 3 penalty points. The course band and who is offered it are in speed awareness course criteria, the penalties in the UK speed camera fine.
Netherlands: deduct 3, then at least 4 over
Under the Openbaar Ministerie's rules, the police deduct a measurement correction of 3 km/h below 100 km/h and 3% above, and then apply a lower limit: nobody is ticketed unless the corrected speed is at least 4 km/h over the limit. Its policy rule 2022A008, in force since 1 July 2022, gives a correction table: 4 km/h for readings of 101 to 133 km/h, 5 for 134 to 166 and 6 for 167 to 200.
OM's own examples: 87 km/h on an 80 road becomes 84, so 4 km/h over and a ticket; one km/h less and there is none. On a 120 road a reading of 128 km/h is corrected by 4 to 124, again 4 over. The rule tells police to set instruments to trigger at 37 km/h for a 30 limit, 57 for 50, 87 for 80, 108 for 100, 128 for 120 and 139 for 130.
Germany: a fixed deduction, a threshold the operator picks
For stationary and transportable radar devices, the Physikalisch-Technische Bundesanstalt (PTB) sets traffic error limits of 3 km/h for readings up to 100 km/h and 3% above (PTB-A 12.04, November 2021). Above 100 km/h the calculated error is rounded up to the next whole km/h in the driver's favour, and it is subtracted from the displayed value to give the speed charged. Our arithmetic: 58 km/h in a 50 zone becomes 55, so 5 over; 108 km/h at a 100 limit gives 3.24, rounded up to 4, so 104; 140 km/h at a 130 limit gives 4.2, rounded up to 5, so 135.
The same document describes an image trigger value that the user of the device selects beforehand, so the speed at which a camera captures a vehicle is the authority's setting, not a legal tolerance.
France: 5 km/h or 5%, always in the driver's favour
ANTAI says fixed, discriminating, mobile and average speed cameras all apply a margin of 5 km/h below 100 km/h and 5% above, "always in favour of the driver". Its example: recorded at 97 km/h, the figure used is 92 km/h. The new-generation mobile cameras in unmarked cars use 10 km/h where the limit is under 100 km/h and 10% where it is above. A margin is not a free buffer there either: Service-Public still lists a fixed fine for an excess under 5 km/h, without points. The camera types, signs and fines are in speed cameras in France.
What BlitzBuddy does
The speed BlitzBuddy shows next to the limit comes from your phone's GPS: a guide, not a calibrated measurement. The limit on the sign is the limit. For official camera maps see speed camera locations and maps, and for the vans that move see mobile speed cameras.
Its camera warnings work in the Netherlands, Belgium, Germany, France and Türkiye. In Germany, § 23 (1c) StVO forbids drivers to use a speed camera warner while driving; the warnings can be switched off under Profile, Warnings, and the driver is responsible. In France, article R413-15 of the Code de la route punishes holding, carrying or using a device that can detect or disturb the equipment used to record traffic offences with a fifth-class fine and the loss of six points, and its paragraph V, added by a decree of 3 January 2012, extends this to devices or products meant to warn of or inform about the location of that equipment; using these warnings is the driver's own responsibility. In the UK, Ireland and every other country, BlitzBuddy gives no camera warnings; your speed, your trips and reports from other drivers still work.
BlitzBuddy is free, with no ads and no subscription. It is available for iPhone; the Android version is coming soon. More camera guides are in the speed cameras topic.
Sources
- Guidance on the Enforcement and Disposal of Speeding Offences (2025), NPCC Roads Policing, version 2.0 (pdf)
- Speeding penalties, GOV.UK
- Marges en meetcorrecties, Openbaar Ministerie (in Dutch)
- Aanwijzing meting snelheidsoverschrijdingen (2022A008), Openbaar Ministerie (in Dutch)
- PTB-A 12.04 Verkehrsradargeräte (stationär, transportabel), November 2021, Physikalisch-Technische Bundesanstalt (in German, pdf)
- Les radars en France, ANTAI (in French)
- Vitesse au volant, Service-Public (in French, verified 29 December 2025)
- StVO, § 23: Sonstige Pflichten von Fahrzeugführenden, Bundesministerium der Justiz (in German)
- Commentaire de la décision n° 2021-948 QPC, Conseil constitutionnel (in French; quotes article R413-15)
- Speed limit data: © OpenStreetMap contributors
Sources read on 17 October 2026.
Frequently asked questions
What is the speed camera tolerance in the UK?
No rule gives one figure. The 2025 NPCC guidance says type approved devices may read up to 2 mph, or 3% above 66 mph, too high, and lists a fixed penalty from 35 mph in a 30 limit and from 79 mph in a 70 limit, while forces may prosecute below those speeds.
Is the UK rule 10% plus 2 mph?
The NPCC guidance does not state that formula. Its fixed penalty speeds for the 20 to 70 mph limits each equal the limit plus 10% plus 2 mph, but it calls them disposal thresholds and warns they have created a pseudo speed limit.
How much is deducted from a camera reading in the Netherlands and Germany?
Under the Openbaar Ministerie's rules the police deduct 3 km/h up to 100 km/h and 3% above, and act only if the result is at least 4 km/h over. For radar devices the PTB requires 3 km/h up to 100 km/h and 3% above in Germany, rounded up in the driver's favour.
Does speed camera tolerance mean I can drive 10% over?
No. A margin covers device error, it is not permission. The NPCC guidance says forces may prosecute below its thresholds, and in France Service-Public lists a fine even for less than 5 km/h over after the margin.
