CP2000 is a federal (IRS) program. It compares the income and deductions reported on your federal tax return with information reported from other sources (e.g., employers, banks, businesses). If the amounts don't match, the IRS adjusts your tax return and mails you a CP2000 notice.
Income and deduction amounts on your Idaho tax return must match those reported on your federal tax return unless an Idaho or federal law says otherwise.
You must contact the Tax Commission if the IRS has adjusted your federal income tax return. You must do this within 120 days of the final federal determination to avoid a negligence penalty. Interest accrues on any amount you owe, starting after the due date of the original return.
You can either:
- File an amended Idaho individual income tax return. Attach a copy of your federal CP2000 notice and any other relevant documents.
- Provide the Tax Commission with a copy of your federal CP2000 notice and any other relevant documents.
Tax Discovery Bureau - CP2000
Idaho State Tax Commission
PO Box 36
Boise ID 83722-0410
IRS notifies Idaho
The IRS forwards information about its CP2000 audits to many states, including Idaho. This can occur years after the IRS contacts you. This is one reason why it's important to contact us promptly. If you don't file an amended return or notify us, we can adjust your return to make it match the IRS's findings at any time in the future.
How Idaho will notify you of the CP2000 adjustment
We'll mail you the Idaho CP2000 Billing Letter if you don't file an amended return. This letter gives you gives you 28 days to either pay or protest.
If you agree with Idaho's calculation of tax, you can either:
- Pay the balance in full. See how to make payments.
- Set up a payment plan. Sign, date, and return the Consent to Assessment (CTA) attached to the Idaho CP2000 Billing Letter. We'll mail you a bill after we receive the signed CTA.
If you don't agree with Idaho's calculation of tax, you have the right to protest. Read about CP2000 protests.
Laws and rules
- Notice of redetermination or deficiency, interest — Idaho Code section 63-3045
- Penalties and additions to the tax in case of deficiency — Idaho Code section 63-3046
- Period of limitations for issuing a Notice of Deficiency and collection of tax -- "...adjusted as a result of a final federal determination..." [Idaho Code section 63-3068(f)]
- Notice of adjustment of federal or state tax liability — Idaho Code section 63-3069
- Credits and refunds -- "...the period of limitations for claiming a refund or credit..." [Idaho Code section 63-3072(d)]
- Income Tax Administrative Rule 890
- Idaho Tax Administration and Enforcement Rule 410
Contact us if you have questions on CP2000 audits.
If you'd like someone else to represent you during your audit, complete and return this Idaho Power of Attorney (POA) form (12-17-2019).