TC 305: Tentative Carryback Allowance by Examination

What the code actually does

IRS Document 6209 defines TC 305 as a credit, "Tentative Carryback Allowance by Exam with Interest Computation Date," Doc Code 47: it "inputs a tentative allowance" and carries a beginning interest computation date, functioning as the examination-side counterpart to TC 295. IRM 21.5.9, Carrybacks, confirms the live current text includes TC 305 in a combined "adjustment principal (i.e., TC 295/299/305,309 sum)" calculation, tying it directly into the same carryback reconciliation the rest of the family uses.

Because it is issued through the examination track, TC 305 typically appears when a carryback claim is filed on a return or module (the IRS's record for one tax period within the account) that Examination Division is already handling, rather than through the ordinary Form 1045/1139 intake that generates a plain TC 295.

Same statute, different processing lane

IRC §6411 governs both TC 295 and TC 305 — the 90-day tentative-refund clock and the limited, pre-audit mathematical review it requires apply regardless of which unit of the IRS actually processes the claim. What differs is administrative: a TC 305 posting means Examination handled the intake, which typically happens when the carryback year, or a year affected by it, is already open for audit.

That distinction carries forward into any later disallowance. A TC 305 allowance can only be reversed by TC 304 (the exam-track disallowance code) — not by TC 294, which is reserved for TC 295. Reading which allowance code is on the module tells you, in advance, which disallowance code a later reversal has to use.

What this means for the account

A TC 305 credit is provisional in exactly the same sense TC 295 is: it is money paid out on a 90-day statutory clock with limited review, not a final determination that the carryback claim is correct. Because it arrived through the examination track, though, it is worth checking whether the same examination already covers other issues on the return — a disallowance of this carryback could surface as part of a broader exam adjustment rather than as an isolated correction.

The amount is also the ceiling on any future TC 304 reversal, exactly as TC 295 caps TC 294 — so knowing the TC 305 figure up front scopes the maximum exposure if the carryback claim does not hold up under full examination.

What TC 305 gets confused with

The clearest mix-up is with plain TC 295, which performs the identical function through routine processing rather than Examination — same interest-computation-date mechanic, same statutory 90-day clock, but a different Doc Code (54 vs. 47) and a different disallowance path (TC 294 vs. TC 304). Which one shows up on the transcript tells a practitioner whether Examination was already involved when the tentative refund was paid.

TC 305 is also not itself an examination assessment — it is a credit that pays money out, the opposite direction from TC 300's debit assessment, even though both ride the same Doc Code 47 examination-processing track.

The practitioner's actual next step

Confirm which examination the TC 305 rode in on, and whether that exam is still open — a disallowance may not surface as a separate TC 304 until the broader audit closes.

Verify the filing date of the underlying Form 1045 or Form 1139 against the IRC §6411 90-day processing window to confirm the allowance itself was timely handled.

Do not treat the TC 305 amount as a closed, final refund — it remains reversible up to that amount through TC 304 for as long as the examination is open.

Pull the complete account history with the IRS Transcript Decoder to see whether a TC 420 examination indicator or a TC 304 reversal already sits alongside this TC 305.