Reviewed and updated 29 July 2026. General owner education, not individual legal, veterinary or behaviour advice.
Start with adult height
The England-and-Wales conformation standard describes adult males from 20 inches (51 cm) at the withers and adult females from 19 inches (48 cm). Enforcement guidance says a dog must meet the minimum height and have a substantial number of the other characteristics to be considered the type.
Look at the whole dog
The standard describes a large, powerfully built dog with a muscular, blocky body and broad head. It then covers muzzle proportions, jaws, neck, forequarters, chest, topline, hindquarters, feet, tail and coat. No single photograph, head shape or chest measurement decides the issue.
What does not prove that a dog is outside the definition
- A microchip record naming another breed.
- A DNA result or breeder-provided pedigree.
- Being described as a crossbreed.
- Having uncropped ears, a particular coat colour or a friendly temperament.
- Matching only one or two visual features.
The law is concerned with physical conformation. Temperament matters enormously to welfare and safe management, but it is not a substitute for the legal type assessment.
How to make a careful preliminary check
Stand the dog naturally on level ground and measure vertically from the ground to the withers, immediately behind the neck. Do not stretch the dog, press down the coat or rely on a photograph taken at an angle. Read the entire official standard and note both matching and non-matching features.
If you are uncertain
Do not publish crowdsourced photographs and treat social-media votes as a legal answer. Contact the relevant police or local-authority dog legislation team and consider advice from a solicitor experienced in dangerous-dogs cases. Only the proper enforcement and court process can determine a disputed case.
Official definition
Read the complete GOV.UK XL Bully conformation standard and its linked enforcement guidance.
Legal information checked against official government guidance on 29 July 2026. Rules can change and individual cases differ. This is general information, not legal advice.
Frequently asked questions
Can a DNA test prove my dog is not an XL Bully?
No. The official process is based on physical conformation rather than a commercial DNA label.
Does height alone decide?
No. Minimum adult height is required, but officials also consider whether the dog has a substantial number of other characteristics.
Does behaviour affect the type assessment?
Temperament is important for handling and welfare, but the statutory type assessment is based on physical characteristics.
