In constitutional law, Advice is formal, usually binding instruction given by a constitutional officer of state to another. Heads of state in particular act on the basis of Advice (frequently capitalised to indicate a formal title of the act) issued by governments and prime ministers.

Among the most prominent forms of Advice offered are:

• Advice to formally dissolve parliament.

• Advice to deliver formal statements, such as a Speech from the throne.

In some isolated cases, constitutional Advice is not binding. For example, many heads of state may opt not to take Advice on a dissolution of parliament where the government has lost the confidence of parliament.