How does a bill become a law? Every new law starts out as an idea, and a bill is a plan for a new law, or a change to an old law. Congress is the part of the national government that makes laws. Congress has two parts: the House of Representatives and the Senate. Let's follow a bill through each step in the House and the Senate, and then see how the United Kingdom makes laws.

Now look back to 1787. In that year, leaders called the Framers met in Philadelphia and wrote the U.S. Constitution. The Great Compromise gave each state equal seats in the Senate and seats in the House based on population. The Great Compromise was approved on July 16, 1787. Each state has two senators, and a state's number of House seats depends on its population.

A bill needs someone to start it. People can ask their lawmakers to start a new law, and a bill can be started by a member of the House or Senate. There is one exception about money. Only the House of Representatives can start a bill about taxes or raising money, although the Senate can still make changes to it. Once a bill is introduced, it is ready for the next stop.

After a bill is introduced, it goes to a committee of lawmakers who study it and can change it. House committees often begin with a public hearing, where members hear witnesses who represent different viewpoints on the bill. After hearings, a House committee holds a "mark-up" session. Members study the viewpoints, may offer amendments, and vote to accept or reject the changes. Then the committee decides what to do with the bill.

A House committee can report a bill, with or without amendments, or table it, which means no further action on it will happen. After a committee releases a bill, the bill is put on a calendar to be voted on, debated or amended. In the House, members debate amendments to a bill and then vote on them. Lawmakers vote on a bill. When the House passes a bill, it goes to the Senate, which studies and votes on it too.

A bill has to pass both the House and the Senate before the president can sign it. If the Senate changes a bill, the House has to look at the changes. The two sides must work out their differences. If the Senate and House pass different versions, a conference committee of members from both can settle the differences and report one identical bill back for a vote in each house. Only then is the bill ready for the president.

Now the bill is in the president's hands. The president can sign a bill into law. The president can say no to a bill, and that is called a veto. Article I, section 7 of the Constitution gives the president the power to veto bills passed by Congress. The Constitution gives the president 10 days, not counting Sundays, to act on a bill. A pocket veto cannot be overridden by Congress.

A regular veto is not always the last word. If the president vetoes a bill, Congress can sometimes vote to override the veto and make it a law. To override a veto, Congress needs a two-thirds vote in each house. The U.S. government has three branches: legislative, executive and judicial. The system of checks and balances lets each branch respond to the actions of the others. The Supreme Court is part of the judicial branch, and it can overturn laws that go against the Constitution.

The Constitution also lists powers for Congress. Congress has the power to collect taxes. Congress also has the power to regulate trade with other nations and among the states. The Tenth Amendment says powers the Constitution does not give to the United States, and does not forbid to the states, belong to the states or to the people. The Constitution says laws made under it are the supreme law of the land, and judges in every state must follow them. Cities and towns can also make laws. Local laws are often called ordinances, and a city council or county commission can pass them.

Other countries make laws in other ways. In the United Kingdom, Parliament makes the laws. A bill must be approved by both the House of Commons and the House of Lords before it becomes an Act of Parliament. As of November 2026, a bill agreed by Parliament has to be approved by the King before it becomes law. In the UK, white papers outline proposals for new laws, and green papers ask for public comments before the white paper is published.

Words to know

• amendments: added changes
• veto: saying no
• committee: study group
• override: cancel a veto
• ordinances: local laws