Title 26 › Subtitle F — Procedure and Administration › CHAPTER 67 — INTEREST › Subchapter A — Interest on Underpayments › § 6603
You can give the IRS a cash deposit that it may use later to pay taxes that have not yet been assessed. The deposit can cover taxes under subtitle A or B or chapters 41, 42, 43, or 44. The IRS will set the rules for how to make the deposit. If the deposit is used to pay tax, the tax is treated as paid at the time you made the deposit for purposes of interest on underpayments. If you ask in writing, the IRS must return any part of the deposit it did not use, unless collecting the tax is in jeopardy. If the deposit is returned, it will count as a payment for interest on overpayments only up to the amount you gave as your reasonable estimate of the maximum tax from disputed items. A disputable item is one you reasonably reported and reasonably think the IRS could disallow. If you got a 30-day letter, that estimate cannot be less than the proposed deficiency in the letter. Interest on returned deposits uses the Federal short-term rate under section 6621(b), compounded daily. Deposits are applied in the order given unless you say otherwise, and returns are made last-in, first-out.
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Internal Revenue Code, Source: USLM XML via OLRC
Legislative History
Reference
Citation
26 U.S.C. § 6603
Title 26, Internal Revenue Code
Last Updated
Sep 22, 2026
Release point: 119-110