DENVER (KDVR) — Colorado Cash Back checks are starting to arrive in mailboxes across the state.

These checks are mainly thanks to the Colorado Taxpayer Bill of Rights, which basically means the state can’t spend more taxpayer money than it generates. Every time the state has a tax surplus and brings in more taxes than it plans to spend, that money is refunded.

Here are five things to know about the checks:

The checks will be a tax rebate of $750 for individual filers and $1,500 for joint filersTo be eligible for the checks you must have been 18 years old on Dec. 31, 2021, and filed a state income tax return for the 2021 tax year before June 30, 2022Extended filers who have a deadline of October 17, 2022, will receive the refund by January 31, 2023You are also eligible if you applied and qualified for a Property Tax/Rent/Heat Credit RebateYour check will arrive at your last known address by Sept. 30, 2022

The Colorado Department of Revenue will be sending approximately 2.4 million checks out.