AP Style holds that capital is a seat of government, usually being a city. Capital can also be used in a financial sense to describe money, equipment, or property in a business of corporation among other uses. For example,
- Washington D.C. is the capital of the United States.
- I need a lot of capital to start my new business.
A capitol, on the other hand, is building where legislators meet to have legislative sessions. AP Style requires “capitol” to be capitalized when referring to the building in Washington where the U.S. Congress meets. It states that this same practice should be followed when referring to state capitol buildings. For example,
- The filibuster was held in the Senate Chamber of the Capitol building.
- The Massachusetts Capitol is in Boston.
If you want to see a more in-depth discussion of the differences between capital and capitol, check our full page on the subject.