01
Jan

Are 4D number plates still road legal?

One of the most common questions drivers ask today is: are 4D number plates legal in the UK? With recent updates to DVLA regulations and stricter standards for number plate manufacturing, it’s no surprise that 3D and 4D plate owners want clarity. The short answer is yes—4D number plates are legal—but only if they comply with the latest rules.

Background: Why the Law Changed

In recent years, interviews with police officers and government updates have raised concerns about the legality of 3D and 4D plates. As car modifications grow in popularity, the DVLA introduced new requirements to ensure plates remain durable, reflective, and compatible with speed cameras and ANPR (Automatic Number Plate Recognition) systems.

The Key Legal Standard: BS AU 145e

Until September 2021, number plates—including 3D and 4D versions—followed the BS AU 145d standard. From September 2021 onwards, all new plates must meet the BS AU 145e standard. This update focuses on:

  • Improved durability against weathering and damage
  • High reflectivity for better visibility day and night
  • Compatibility with speed cameras and ANPR systems
  • Stricter rules on font style and plate design

Are Existing 4D Plates Still Legal?

If you bought your 3D or 4D number plates before September 2021, they remain legal to use provided they complied with the BS AU 145d rules at the time. However, any new 3D or 4D plates purchased after September 2021 must meet the BS AU 145e standard to stay road-legal.

What’s Not Allowed Under the New Rules

While genuine 3D and 4D plates are still legal, some styles are now banned. Specifically:

  • 2D printed plates designed to imitate 3D or 4D effects are illegal.
  • Two-tone shading or “fake 3D” effects are prohibited, as they reduce ANPR readability.
  • Plates without the supplier’s name and postcode are non-compliant.
  • Plates that do not display “BS AU 145e” in the bottom right corner are not road-legal.

Other Requirements You Must Meet

In addition to BS AU 145e compliance, your number plate must:

  • Use the correct font (Charles Wright font) with standard spacing
  • Not have a background pattern or tinted covering
  • Include the supplier’s details and postcode
  • Remain clean, readable, and unobstructed at all times

So, Are 4D Number Plates Legal?

The clear answer is: Yes, 4D number plates are legal in the UK—as long as they meet the DVLA’s BS AU 145e requirements. If your plates were purchased before September 2021, they remain legal under previous rules. If you’re buying new ones, make sure they come from a registered supplier who guarantees compliance with the latest standards.

Final Thoughts

While the law around number plates has tightened, the DVLA update doesn’t ban 3D or 4D styles—it simply ensures that all number plates are durable, reflective, and easy to read by both humans and cameras. If you stick to approved suppliers and make sure your plates carry the “BS AU 145e” mark, you can enjoy your 4D plates without worrying about penalties or MOT failures.