68 O.S. Section 2357.206
The aggregate credits cannot exceed $3.5 million annually for donations to an eligible scholarship-granting organization and $1.5 million annually for donations to an educational improvement grant organization. If total combined credits claimed for contributions to one organization exceed the cap for that organization, credits not claimed for the other organization may be allocated to the first organization, but no more than $5 million in total credits may be claimed annually. If the Tax Commission determines the total combined credits claimed for contributions to both eligible scholarship-granting organizations and eligible educational improvement grant organizations exceed $5 million, the Tax Commission shall determine the percentage of the contribution which establishes the proportionate share of the credit which may be claimed by any taxpayer so that the maximum credits authorized are not exceeded. The credit cannot reduce the tax liability of the taxpayer to less than $0, but any credits allowed but not used in any tax year may be carried over to each of the three (3) years following the year of qualification.
2021 Credit Information
Scholarship-granting organization
For tax year 2021, contributions made to scholarship-granting organizations must be multiplied by 85.6% before the applicable percentage (either 50% or 75%) is applied to calculate the credit. Credits limited under the 85.6% limitation may be carried over to the next tax year. The amount of credit is not to exceed $1000 for a taxpayer filing single or $2000 for a taxpayer filing jointly.
More information can be found on the Oklahoma Tax Commission website.