ICYMI via the Tax Foundation:

Some lawmakers have expressed concerns about President Biden’s proposal to raise the federal corporate income tax rate from 21 percent to 28 percent, and instead suggest raising the rate to 25 percent. Including state corporate taxes, a 25 percent federal corporate income tax rate would result in a combined average top corporate tax rate of 29.53 percent—higher than the 23.51 average among industrialized countries in the OECD. In some states, the combined top corporate tax rate would be higher than in any other country in the industrialized world.

Under current law, corporations in the United States pay federal corporate income taxes levied at a 21 percent rate plus state corporate taxes that range from zero to 11.5 percent, resulting in a combined average top tax rate of 25.8 percent in 2021.

The highest combined corporate tax rate in the OECD is levied by France, at 32 percent. Next year, France will lower its corporate tax rate to 25.8 percent, leaving Portugal with the highest corporate tax rate in the OECD at 31.5 percent. If the federal corporate tax rate were increased to 25 percent, nine states would have combined federal-state top corporate income tax rates exceeding 31.5 percent.

It is important to include state corporate income taxes when considering how raising the federal rate would impact U.S. competitiveness. A higher corporate tax rate would make the U.S. less competitive as a location for corporate investment and would reduce economic output, jobs, and wages across the income spectrum.