What happens if I am caught doing 45 in a 30?

It is above the 42 mph top of the course window, so the usual disposal is a fixed penalty of £100 and 3 points rather than a course.

How many points is 45 in a 30?

Band B carries 4 to 6 points, or the court can disqualify instead: disqualify 7 to 28 days. A fixed penalty, where one is offered, is 3 points.

How is the fine worked out?

As a percentage of relevant weekly income: a starting point of 100 per cent within a range of 75 to 125 per cent. It is capped at £1,000, or £2,500 on a motorway.

Does the speedometer reading matter?

No. The recorded speed is what the device measured. Type approved devices are allowed a positive error of 2 mph, or 3 per cent above 66 mph, which is a measurement allowance rather than a permitted margin over the limit.

Speeding

45 mph in a 30 mph limit

Worked from the Sentencing Council guideline and the NPCC enforcement table, which answer two different questions about the same journey.

Band B

Sentencing Council band

Sentencing Council for England and Wales, Speeding (Revised 2017) (as of 24 April 2017)

4 to 6 points

Points if convicted

Sentencing Council for England and Wales, Speeding (Revised 2017) (as of 24 April 2017)

Fixed penalty

What usually happens

National Police Chiefs' Council, Guidance on the enforcement and disposal of speeding offences (2025), version 2.0 (as of 31 July 2025)

Checked on 7 September 2026.Sentencing Council for England and Wales, Speeding (Revised 2017) (as of 24 April 2017)

Is 45 mph in a 30 mph limit band A, B or C?

Band B. On a 30 mph limit the guideline puts 31 to 40 mph in band A, 41 to 50 in band B and 51 and above in band C, and 45 falls in band B.

The band decides the sentence only if the case reaches a magistrates' court. Most speeding is dealt with by a fixed penalty or a course, and neither of those is set by the guideline.

What band it carries

Band B penalties from the speeding guideline

Fine starting point	100 per cent of relevant weekly income
Fine range	75 to 125 per cent of relevant weekly income
Penalty points	4 to 6 points
Disqualification	Disqualify 7 to 28 days
Statutory maximum	£1,000, or £2,500 on a motorway

What the fine would be at three incomes

Band B fine at three weekly incomes
Weekly income after tax	Starting point	Range
£300	£300	£225 to £375
£500	£500	£375 to £625
£900	£900	£675 to £1,000

A court with no information about income assumes £440 a week. Where the only source is state benefit, or net income is £120 a week or less, the income is deemed to be £120.

Where this speed sits on the enforcement table

45mph in a 30mph limit sits in band B of the Sentencing Council grid.
This is above the 42mph top of the course window and below the 50mph point at which the NPCC table sends every case to court, so a £100 fixed penalty and 3 points is the usual disposal.
No weekly income was given, so the fine is shown as the guideline shows it, as a percentage of relevant weekly income. A court with no information at all assumes £440 a week.
The fine is capped at £1,000, and at £2,500 where the offence was on a motorway.

Common questions

What happens if I am caught doing 45 in a 30?: It is above the 42 mph top of the course window, so the usual disposal is a fixed penalty of £100 and 3 points rather than a course.
How many points is 45 in a 30?: Band B carries 4 to 6 points, or the court can disqualify instead: disqualify 7 to 28 days. A fixed penalty, where one is offered, is 3 points.
How is the fine worked out?: As a percentage of relevant weekly income: a starting point of 100 per cent within a range of 75 to 125 per cent. It is capped at £1,000, or £2,500 on a motorway.
Does the speedometer reading matter?: No. The recorded speed is what the device measured. Type approved devices are allowed a positive error of 2 mph, or 3 per cent above 66 mph, which is a measurement allowance rather than a permitted margin over the limit.