IRS Letters and Forms
CP133

CP133 — Math error on Form 1120 series, 1041, Form 8804, 990-C or 990-T resulting in a net overpayment.

Math error on Form 1120 series, 1041, Form 8804, 990-C or 990-T resulting in a net overpayment.

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CP133

Read the notice carefully and note any deadline. Gather returns, notices, and payment records. Book a free strategy session before responding if the amount is large, unclear, or collection language appears.

What the IRS language says

Math error on Form 1120 series, 1041, Form 8804, 990-C or 990-T resulting in a net overpayment.

What it usually means

CP133 is in our IR Manual catalog. Official wording is dense — we translate it for business owners and individuals and map realistic next steps.

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