Number plates are not just cosmetic — they are a legal requirement governed by strict regulations. Get it wrong and you face a fine of up to £1,000, an MOT fail, and potentially having your car's registration revoked.

1. Legal Font and Spacing

All UK number plates must comply with BS AU 145e, the British Standard for number plates. This means:

  • Characters must use the mandatory Charles Wright font — no other fonts are permitted
  • Characters must be 79mm tall and 50mm wide (except for 1 and I)
  • Character stroke width: 14mm
  • Space between characters: 11mm
  • Space between groups (e.g., AB12 and CDE): 33mm
  • Margins: 11mm minimum on all sides

2. Colour Rules

  • Front plate: White background with black characters
  • Rear plate: Yellow background with black characters
  • Both must be made of reflective material
  • Electric vehicles may display a green flash on the left side (optional)

3. Reflective Material Requirement

Plates must be made of approved reflective material. This ensures they are visible at night when illuminated by headlights. Non-reflective plates are illegal and will fail the MOT.

4. Illegal Modifications

⚠️ These Are All Illegal
  • Altered spacing to make a word or name (e.g., "M1 KE" instead of "M1KE")
  • Fancy fonts, 3D gel characters that obscure readability, or italic styles
  • Screw heads or fixings that obscure characters
  • Tinted or smoked plates
  • Non-standard colours (chrome, carbon fibre effect, etc.)
  • Flags or symbols in non-approved positions

The fine for illegal plates is up to £1,000, and the car will fail its MOT. ANPR cameras may also be unable to read modified plates, which can result in additional enforcement action.

5. Personalised and Private Plates

You can buy personalised number plates from the DVLA or from private dealers. The process:

  • Purchase the registration number (from £250 at DVLA auctions, or from dealers)
  • Assign it to a vehicle using form V750 or V778 (online or by post)
  • Pay the £80 assignment fee
  • Get new plates made by a registered supplier

Important rule: You cannot make a car appear newer than it is. A 2018 car can display a 2018 or older plate, but not a 2024 plate.

Pro Tip: If you want to keep a personalised plate when selling a car, apply for retention using form V778. The plate is held on a certificate for 10 years (£80 fee). You must do this before the car is sold.

6. Display Rules

  • Plates must be clearly visible and clean at all times
  • The rear plate must be illuminated at night (built into the car's lighting)
  • Both plates must be securely fixed and not obscured by tow bars, bike racks, etc.

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7. MOT and Number Plates

Number plates are checked during the MOT. Your car will fail if:

  • Characters are not in the correct font or size
  • Spacing has been altered
  • The plate is faded, damaged, or not reflective
  • The rear plate light is not working
  • The plate does not match the V5C registration number

8. Replacing Damaged or Faded Plates

If your plates are damaged, faded, or no longer legible, you must replace them. Go to any registered number plate supplier (RNPS) with proof of entitlement:

  • V5C logbook
  • V5C/2 green slip
  • Certificate of entitlement (V750 or V778)
  • Or a valid insurance or finance document showing the registration

Replacement plates typically cost £15–£30 per plate.

Final Thoughts

Number plate rules in the UK are strict and heavily enforced through MOT testing and ANPR cameras. Stick to the standard format, keep your plates clean and legible, and never modify the spacing or font. The £1,000 fine is not worth the personalisation.

For the full legal requirements, see gov.uk/displaying-number-plates.

Frequently Asked Questions

UK number plates must use the mandatory Charles Wright font as specified in BS AU 145e. No other fonts, italic styles, or decorative characters are permitted. The characters must be a specific size: 79mm tall and 50mm wide (except the number 1 and letter I).
No. Front plates must be white with black characters. Rear plates must be yellow with black characters. Both must be made of reflective material. Tinted, smoked, or coloured plates are illegal and will result in an MOT fail and a potential fine.
DVLA personalised plates start from £250 at auction. Private plates from dealers start from around £150 for less desirable combinations, up to hundreds of thousands for premium plates. The transfer fee is £80 to assign a plate to a vehicle.
No. Number plates must follow strict spacing rules. Characters must be evenly spaced within the plate, and the group spacing must comply with regulations. Altered spacing to make a plate spell a word or name is illegal and carries a £1,000 fine.
You must replace damaged or faded plates promptly. They must remain legible and comply with current regulations. An unreadable plate will fail the MOT. You can get replacement plates from any registered number plate supplier by showing your V5C or other acceptable identification.

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