The Governor of Colorado signed Bill SB24-228 into law on 14 May 2024. It introduces significant amendments concerning the refund of excess state revenues.

This legislation reduces both individual and corporate income tax rates from 4.40% to 4.25%, effective for the income tax year beginning 1 January, 2024.

Furthermore, for state fiscal years starting on or after 1 July, 2024, and before 1 July, 2034, the income tax rate will be subject to additional reductions based on excess state revenues. These reductions will be applicable to the income tax year coinciding with the end of the relevant fiscal year.

Depending on the amount of excess state revenues, the income tax rate may be decreased between 0.04% and 0.15% annually.