The law states that anyone in possession of magical abilities, therefore a witch or wizard, under the age of seventeen years of age is banned from using magic outside of school. This is part of the Decree for the Reasonable Restriction of Underage Sorcery of 1875. Various restrictions and alterations have been made to the law since it was first subjected.

Underage magical beings have the “trace” locked on them until they are of age as well. This means that the Ministry of Magic is able to find out if they have performed illegal magic, and where it came from. Students will get a letter and their wands and homes are often restricted as well especially if there are muggles living in or around the house. Whilst I was young the trace hardly affected me. The main house we lived in was in the most magical neighbourhood you could find. Otherwise it was surrounded by muggles with over-age wizards or witches residing in it.

Luckily when you are a metamorphmagus they take any change in your body to be simply a sign of ability. Therefore, I was able transfigure not only myself but other things whilst under the trace and not be recognised.

Letters that are sent to people warning them or informing them of expulsion are along the lines of:

Dear (insert name)

The Ministry of Magic has received intelligence that you performed the (insert type of spell)
at (insert time) today,
in (insert place) if muggles were around then this must also bee taken into account.

The severity of this breach of the Decree for Reasonable Restriction of Underage Sorcery has resulted in you expulsion from…

Ministry officials will be calling shortly to destroy your wand.

Yours Sincerely,
(insert name of sender)

Improper Use of Magic Office,
Ministry of Magic.