Hello. Here are the regulations on hair in the British Army;

General guidelines. The hair of the head of both males and females in uniform is to be neat, trimmed and worn above the collar in a manner that is compatible with the professional image of the Army. The style and colour of the hair (if not natural) is not to be of an exaggerated nature. The hair is to be worn such that all types of military headdress may be worn in the correct manner. Hair should not be visible on the forehead under the brow band of the headdress nor seen on or covering the ears. Exceptions will only be granted on religious grounds detailed in AGAI 59, Annex B or at the discretion of the CO.
(a) Males. Male hair is to be cut short such that its length does not reach to the collar or onto the ears. Males are to be clean-shaven but moustaches and beards may be worn. If a moustache is worn, it is to be trimmed and not below the line of the lower lip. Beards and whiskers are only to be worn with the CO’s authority, which will usually be granted only on medical or religious grounds, or where tradition permits. The appearance of the beard and whiskers is to be neat and tidy. Sideburns are not to descend below the midpoint of the ear and are to be trimmed horizontally.
(b) Females. Female hair may be long but when in uniform, it is to conform to the general guidelines above. Combs, grips etc if worn, are to be plain and similar in colour to the hair. A hair net (if worn) is to be of the same colour as the hair.

From my understanding, it would be up to your chain of command if you can have dreadlocks or not but I would expect the worst and not be permitted to have them.
I hope this helps
Zoe

02 March, 2020 10:48