The much-quoted 180 days is an outer limit, and treating it as a date is the first error. The retail credit policy directs that "open- and closed-end retail loans past due 90 cumulative days from the contractual due date should be classified Substandard," and that "closed-end retail loans that become past due 120 cumulative days and open-end retail loans that become past due 180 cumulative days from the contractual due date should be classified Loss and charged off." But the same policy opens with the sentence that governs both: actual credit losses "should be recorded when the institution becomes aware of the loss, but in no case should the charge-off exceed the time frames stated in this policy," and it adds that nothing precludes an institution from adopting a more conservative internal policy. So a charge-off can come sooner, the day counts are the latest it may come, and 180 days is not a period a borrower is entitled to.
A footnote to the same provision handles the calendar mechanics: whenever a charge-off is necessary, "it should be taken no later than the end of the month in which the applicable time period elapses." Several situations override the ordinary ladder. A loan in bankruptcy is charged off within 60 days of notice from the bankruptcy court or within the policy's time frames, whichever is shorter, unless repayment can be clearly documented as likely. A fraudulent loan is charged off no later than 90 days after discovery. Loans of deceased persons are charged off when the loss is determined. And an open-end account placed on a fixed repayment schedule follows the closed-end timetable rather than the revolving one.
What actually changes at charge-off is the creditor's relationship to the account, and that is why a stranger calls. Once the balance is a recognized loss rather than an earning asset, holding it has no upside, so creditors ordinarily either refer the account to an agency for a commission or sell the file outright at a steep discount. That handoff is the practical meaning of a charge-off for the person who owes the money, and what the new caller may and may not do is the subject of the debt collection page. The one thing a charge-off does not do is transfer the obligation: whoever holds it, it is the same debt on the same terms.
A charge-off is not a tax event, and the distinction is written into the regulation. Reporting on Form 1099-C is triggered by an identifiable event, and 26 CFR 1.6050P-1(a)(1) says a discharge is deemed to have occurred "if and only if there has occurred an identifiable event described in paragraph (b)(2)." That list, at (b)(2)(i), has seven entries: a discharge in a title 11 bankruptcy case; a cancellation that renders the debt unenforceable in a receivership, foreclosure or similar court proceeding; the expiration of the limitation period for collection, subject to a further condition; an extinguishment on a creditor's election of foreclosure remedies; unenforceability under a probate or similar proceeding; an agreement between creditor and debtor to discharge the debt at less than full consideration; and a decision or defined policy to discontinue collection activity and discharge the debt. A charge-off appears nowhere on it.
Be careful with the last entry, though, because the two events can coincide. Paragraph (b)(2)(iii) says a creditor's defined policy includes an established business practice, and gives as its example "a creditor's established practice to discontinue collection activity and abandon debts upon expiration of a particular non-payment period." So a creditor whose practice is to stop pursuing a debt at the same moment it charges it off can generate a reportable discharge. The accurate statement is that a charge-off is not itself the trigger, not that a 1099-C never follows one.
Two cautions about what a charge-off does not mean, both of which are worth more than the day counts. It is not a consumer protection or a statutory process, so there is no procedure to invoke and no notice a borrower is entitled to receive on account of it. And the interagency policy itself is supervisory guidance from the federal banking agencies to the institutions they supervise, about how those institutions grade their own assets; it does not create obligations that run to a borrower. Separately, when the item reaches a credit report, how long it may stay there is a Fair Credit Reporting Act question with its own clock and its own starting point, which the credit report page carries in full.