Internal Revenue Service
Website: https://www.irs.gov/
Phone number: (800)-829-1040
Where’s my refund: https://www.irs.gov/refunds
Missouri Department of Revenue
Website:https://dor.mo.gov/
Phone number refund or no balance due: (573) 751-3505
Phone number balance due: (573) 751-7200
Automated Inquiry: (573) 526-8299