Note: Because of a minor bug in 18.1.0.0, we released 18.1.0.1 after the earlier version was online for a few hours. Read more

Both Release 18.1.0.0 and 18.1.0.1 reflect the following changes effective January 1, 2018:

• Alaska reverted to a single rate for all corporate income taxes and converted calculation of non-Oil and Gas Production to quarterly compounding. The interest rate was set at 7.25%.
• Georgia changed from 6.75% to 7.50% for both underpayments and overpayments.
• Idaho changed from 3.00% to 4.00% for both underpayments and overpayments. Note: This was included in the 17.4.0.0 and 17.4.0.1 releases.
• Iowa changed from 5.00% to 6.00% for both underpayments and overpayments.
• Kentucky changed from 5.00% to 6.00% for underpayments and from 1.00% to 2.00% for overpayments.
• Louisiana changed from 7.25% to 8.00% for underpayments and from 4.25% to 5.00% for overpayments.
• Maryland changed from 12.00% to 11.50% for both underpayments and overpayments.
• Maine changed from 7.00% to 6.00% for both underpayments and overpayments.
• Michigan changed from 4.70% to 5.15% for both underpayments and overpayments. Note: This was included in the 17.4.0.0 and 17.4.0.1 releases.
• Missouri changed from 0.80% to 0.90% for overpayments; the underpayment rate remained unchanged at 4.00%.
• New Jersey changed from 6.50% to 7.25% for underpayments and from 3.50% to 4.25% for overpayments.
• Rhode Island changed from 3.50% to 4.25% for overpayments; the underpayment rate remained unchanged at 18.00%.
• Texas changed from 4.75% to 5.50% on underpayments and from 1.004% to 1.429% on overpayments.
• Vermont changed from 5.60% to 6.00% on underpayments and from 3.60% to 4.00% on overpayments.
• West Virginia changed from 8.00% to 8.75% on underpayments and from 6.50% to 7.25% on overpayments.