Standard - The tail is moderately long, set on low, well furnished and with an upward swirl towards the end, completing the graceful contour and balance of the dog. The tail may be raised in excitement, but not carried over the back.

A correctly set, well carried tail, with sufficient furnishings, is most important in the assessment of overall balance of the Border Collie. If he carries his tail high, his balance is affected and he loses his smooth flowing movement, sometimes having an ungainly rear action. You may also find that he has a high set on tail.

Carriage of the tail is the result of -

a. Correct length and angle of croup
b. Correct tail set and length
c. Changes in direction of travel when on the move
d. Disposition of the dog.

The bone of the tail should reach at least to the hock joint with no kinks or knots. When on the move the tail should ideally be carried horizontally or lower than the line of the back.

The (upward) swirl in the tail is a feature of this breed, as is the white tip on the end of the tail.

The moderately long, low set tail of the Border Collie (with its upward swirl, whilst the dog is moving) is not only a feature of this breed, but serves a functional purpose as well. While concentrating at a given task the tail is carried low and is used almost like a rudder to help balance the dog when turning. Consequently judges should be aware that tails which are too short lack functional usefulness.