Glossary

Illinois Department of Revenue (IDOR)

The Illinois Department of Revenue is the state agency that administers Illinois income, sales and use, and excise taxes, conducts state audits, and pursues collection separately from the IRS.

How it works

IDOR administers Illinois income, sales and use, and excise taxes, conducts state audits, and pursues collection separately from the IRS. Illinois audits often follow or trigger federal ones. The state has its own notices, appeal deadlines, the Informal Conference Board, and the Board of Appeals for penalty and interest relief, and it can revoke business registrations and licenses for unpaid tax.

Why it matters

Resolving the IRS does not resolve Illinois, and state collection tools are aggressive and fast.

Related: Illinois sales and use tax audit. Read more: how to stop an Illinois tax levy.

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Definitions are general information, not legal advice, and may not reflect the most recent changes in law.

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