The U.S. Congress is split into two chambers with very different jobs. When comparing Senate vs. House roles, powers, and structure, the shortest answer is this: the House has 435 members on two-year terms and controls the start of revenue bills and impeachment charges; the Senate has 100 members on six-year terms and controls confirmations of presidential nominees, approval of treaties, and impeachment trials. Both must pass identical bill text before anything becomes law, so neither chamber can act alone.
How the Two Chambers Are Built
The House seats 435 voting members, a number fixed by the Permanent Apportionment Act of 1929.1Congress.gov. Size of the U.S. House of Representatives Seats are divided among the states by population, using the census taken every ten years, and district lines are redrawn afterward. Fast-growing states pick up seats; shrinking states lose them. Six non-voting delegates also sit in the House, representing the District of Columbia, Puerto Rico, Guam, American Samoa, the U.S. Virgin Islands, and the Northern Mariana Islands. They can introduce bills, speak, and vote in committee, but they cannot vote on final passage.2Congress.gov. Delegates to the U.S. Congress: History and Current Status
The Senate seats 100 members, two from every state regardless of population. Wyoming and California each get two. That equal-state rule is baked in.
Qualifications differ. A House member must be at least 25, a U.S. citizen for seven years, and a resident of the state they represent.3Constitution Annotated. Article I Section 2 A senator must be at least 30, a U.S. citizen for nine years, and a state resident.4Constitution Annotated. Article I Section 3 Clause 3
Terms differ too. Representatives serve two-year terms and every House seat is on the ballot every even-numbered year, which keeps House members closer to voters. Senators serve six years with staggered elections, so roughly one-third of the Senate faces voters every two years. The longer term was designed to give senators room to focus on longer-range policy.
Vacancies are handled differently. When a House seat opens mid-term, the governor of the state must call a special election; there is no appointed replacement.5Constitution Annotated. House Vacancies Clause Under the 17th Amendment, senators are elected directly, and state legislatures can authorize the governor to appoint a temporary Senate replacement until a special election is held.6Constitution Annotated. U.S. Constitution – Seventeenth Amendment Most states have granted their governors that appointment power.
One eligibility bar applies to both chambers: Section 3 of the 14th Amendment blocks anyone who previously swore an oath to the Constitution as a federal or state official and then engaged in insurrection or rebellion. Only a two-thirds vote of each chamber can lift it.7Constitution Annotated. Section 3 – Disqualification from Holding Office
What Only the House Can Do
Start Revenue Bills
The Origination Clause in Article I, Section 7 requires that every bill raising revenue begin in the House. The Senate can amend those bills once they arrive, but the first move belongs to the chamber whose members face voters every two years.8Constitution Annotated. Article I, Section 7, Clause 1
Impeach Federal Officials
The House alone can impeach the President, Vice President, federal judges, and other federal officers. Members investigate alleged misconduct and draft articles of impeachment, which function as formal charges. A simple majority approves the articles.9U.S. Senate. About Impeachment Impeachment itself does not remove anyone. It is closer to an indictment, and the case then moves to the Senate.
What Only the Senate Can Do
Confirm Presidential Nominees
The Constitution gives the Senate “advice and consent” over presidential nominations. Cabinet members, federal judges, ambassadors, and other senior officials go through committee hearings and a Senate floor vote, and a simple majority confirms.10Constitution Annotated. Article II Section 2 Clause 2 Rule changes in 2013 and 2017 let a simple majority end debate on all nominations, including Supreme Court justices, so the old 60-vote hurdle no longer applies to nominees.11Congress.gov. Senate Consideration of Presidential Nominations The House has no role in confirmations.
Approve Treaties
Treaties negotiated by the President need Senate approval, and the threshold is high: two-thirds of senators present must vote yes. Technically the Senate votes on a resolution of ratification, which the President then uses to finalize the agreement.12U.S. Senate. About Treaties The House does not vote on treaties.
Try Impeachments
After the House impeaches, the Senate conducts the trial. Senators sit as jurors, hear evidence, and vote on conviction. A two-thirds supermajority is required to convict and remove the official from office, and the Senate may then vote separately to bar the person from future federal office.9U.S. Senate. About Impeachment
Filibuster and Cloture
Senate rules allow unlimited debate on most legislation, which lets a senator or group stall a bill by refusing to yield. Cutting off debate requires a cloture vote, which needs 60 of 100 senators.13U.S. Senate. About Filibusters and Cloture Final passage still needs only a simple majority, but reaching the vote often requires 60. The House has no comparable rule, which is why bills sometimes pass the House quickly and stall in the Senate.
Powers the Two Chambers Share
Making Laws
A bill can start in either chamber, except revenue bills, which must start in the House. It gets referred to a committee, which may debate, amend, or shelve it. If the committee sends it forward, the full chamber votes. Both chambers must pass identical text before anything reaches the President. When their versions differ, a conference committee of members from both sides negotiates a single unified text, which then goes back to each chamber for a final vote with no further amendments.14House.gov. The Legislative Process
If the President signs, the bill becomes law. If the President vetoes, the bill returns to its chamber of origin. Overriding a veto requires two-thirds of both the House and the Senate, and overrides are rare because that bar is so high.15Constitution Annotated. Veto Power
Controlling Federal Spending
Congress controls the money. No funds can be drawn from the Treasury except through appropriations made by law.16Constitution Annotated. Article I Section 9 The President proposes a budget, but Congress decides what actually gets funded. The federal fiscal year starts October 1, and when Congress misses that deadline on spending bills, agencies either operate under temporary continuing resolutions or shut down.
Declaring War
Only Congress can declare war. It has done so 11 times, most recently during World War II.17U.S. Senate. About Declarations of War by Congress Since then, military action has been authorized through joint resolutions. The War Powers Resolution of 1973 requires the President to notify Congress within 48 hours of committing armed forces to hostilities and to withdraw them within 60 days unless Congress authorizes continued action or declares war. The President can extend that window by 30 days if needed for a safe withdrawal.18Office of the Law Revision Counsel. 50 USC Ch. 33: War Powers Resolution
Oversight of the Executive Branch
Both chambers can investigate how the executive branch carries out the law. The Supreme Court has recognized this authority as essential to the legislative function, though it is not spelled out in the Constitution. Committees hold hearings, compel testimony, and issue subpoenas, provided every investigation serves a legitimate legislative purpose.19Constitution Annotated. Overview of Congress’s Investigation and Oversight Powers
Leadership That Shapes How Each Chamber Runs
The Speaker of the House is chosen by the House itself and is the chamber’s most powerful figure. The Speaker presides, refers bills to committees, recognizes members to speak, and rules on procedural disputes.20U.S. Government Publishing Office. House Practice: A Guide to the Rules, Precedents and Procedures The Speaker also stands second in the presidential line of succession, behind the Vice President, and in practice leads the majority party and controls what legislation reaches the floor.
The Senate’s presiding officer is officially the Vice President of the United States, who only votes to break a tie. Day-to-day presiding falls to the President Pro Tempore, traditionally the longest-serving member of the majority party, who administers oaths, signs legislation in the Vice President’s absence, and makes appointments to advisory boards and commissions.21U.S. Senate. About the President Pro Tempore The real operating power belongs to the Majority Leader, who controls the floor schedule, decides which bills come up, and negotiates time agreements with the Minority Leader. The Majority Leader also holds the right of first recognition, meaning they can offer amendments and motions before any other senator.22U.S. Senate. About Parties and Leadership: Majority and Minority Leaders
Much of the actual legislative work happens in committees rather than on the floor. Committees hold hearings, question witnesses, draft bills, and decide which proposals move forward. Only a small share of bills referred to committees ever reach a floor vote, which is where most legislation quietly dies.23U.S. Senate. About the Committee System