There is only one change effective October 1, 2024. The Missouri refund rate changed from 3.10% to 3.20%; the underpayment rate remained unchanged at 9.00%.

Two rates were announced effective January 1, 2025, and these rates have been included in this release:

• Nebraska will change from 5.00% to 8.00% for both underpayments and overpayments.
• New Hampshire will change from 9.00% to 10.00% for underpayments and from 6.00% to 7.00% for overpayments.

Colorado had previously announced a change from 11.00% to 12.00% for both overpayments and underpayments; this change was included in the 24.3.0.0 release.