Bills v Acts. A Bill is not an Act of Parliament. This is what a Bill becomes if approved by a majority in the House of Commons and the House of Lords, and formally agreed to by the reigning monarch (known as Royal Assent).An Act of Parliament is a law, enforced in all areas of the UK where it is applicable.ills v Acts. A Bill is not an Act of Parliament. This is what a Bill becomes if approved by a majority in the House of Commons and the House of Lords, and formally agreed to by the reigning monarch (known as Royal Assent).