An enforcement notice does not expire. It must allow for a four-week (minimum) period for you to appeal before coming into effect. If no appeal is made, the notice will come into effect. NEVER ignore an enforcement notice. Should you receive one, we strongly recommend enlisting a professional planning consultant.
The compliance period for an enforcement notice is variable, depending on the nature of the development. This can range from one month for simple works reversal, through to six months for usage changes and land restoration. Only in the rarest of circumstances will the compliance period exceed six months. You must comply with the terms of the enforcement notice.