IRS Internet Resources

The IRS website is The following items are among those available on the site.

The redacted IRS guide for internal use, Document 6209, IRS Processing Codes and Information, is available to the public for the past 7 or 8 publication years. This document contains the Transaction Codes used on tax account transcripts and a wealth of other information. It explains, for example, how the Document Locator Number (DLN) is constructed and the categories to which the groups of digits in the DLN refer.

Transaction Codes often encountered on estate tax return transcripts include the following (arranged in the chronological order in which they might occur) :

670 Payment with Form 4768 before the return is filed, or a payment subsequent to the return filing, e.g. an annual payment on a section 6166 anniversary date.
150 Tax assessed when the original return is filed.
610 Payment submitted with the original return. Sometimes posted with §6166 anniversary date payments instead of the appropriate TC 670.
340 Manually computed interest assessment in 6166 cases, inter alia. (Section 6166 interest amounts are not automatically generated by the IRS computer system.) TC 340 is always associated with a TC 290 for zero on an IRS transcript in a normal §6166 case - the TC 290 zero is a clearing function for the computer system so that the TC 340 amount will post.
290 Posting with a dollar amount indicates a Campus tax assessment (increase) in response to either a math error correction during the original return processing or a supplemental return reporting a tax increase. This can occur before field examination activity has been completed.
291 A tax decrease assessed at a Campus. This generally will not occur before the examination of the original return has been completed because the account will show an unreversed TC 420 (the Examination Activity Code indicator which is assigned to every estate tax return). See e.g. Estate of Shapiro v. U.S.,111 F. 3rd 1010. Supplemental returns received before an examination has been completed will be forwarded by Campus to the examining IRS Estate Tax Attorney for consideration.
300 Tax assessment (increase) resulting from a field examination. Will post with zero in a No Change or No Change With Adjustment examination case.
301 Tax assessment (decrease) resulting from a field examination.
976 A supplemental return filing. A dollar amount posted indicates a payment with the supplemental return.
166 Computer generated §6651(a)(1) failure to file penalty - TC 160 if manually computed. Reversed by TC 167 or TC 161.
276 Computer generated §6651(a)(2) failure to pay penalty - TC 270 if manually computed. Reversed by TC 277 or TC 271.
240 Manually computed Miscellaneous Penalty. Used for §6166(g)(3) late payment penalty assessments and §6662(b)(5) estate or gift tax valuation understatement penalty assessments, among others. The TC 240 penalty assessment for a §6166(g)(3) failure to pay principal or interest is automatically reversed - abated - by TC 241 when an estate fails to make payment within 6 months of the date on which such payment was due, because the estate loses its §6166 election. The §6166(g)(3) penalty applies only if the estate keeps its §6166 election.

Note: Failure to make payment does not automatically terminate a §6166 election; the IRS must first issue a final Notice and Demand for payment. Under normal procedures, a notice and demand for payment is sent every 45 days during the 6-month period in which an estate can save its §6166 election (by paying the past-due installment plus penalties and interest). By the 180th day the final notice and demand for payment would be sent with a specific payment deadline, after which the section 6166 account would be accelerated; the payment deadline specified in that letter would be the date on which the election is terminated under section 6166(g)(3). See United States v. Godley, 3:13-cv-549-RJC-DCK, W.D.N.C., Sep-30-2015.

If for some reason the IRS fails to send the final Notice and Demand until well beyond the 180th day, the estate's §6166 election would remain in effect until the acceleration date specified in that final Notice and Demand.

Forms 706 and Forms 709 and their instructions - and IRS Publications - are available for the current year, as well as for prior years going back to, for example, 1993 for Form 706 or 1962 for Form 706-NA, or back to 1955 for Form 709

Form 4768, Application for Extension of Time to File a Return and/or Pay U.S. Estate (and Generation-Skipping Transfer) Taxes, is used to request an extension of time to file the estate tax return, and also to request an extension of time to pay the estate tax (a separate request must be made on the Form for each type of extension). Form 4768 can also be filed to request an extension of time to pay an annual installment due under a section 6166 deferral. NOTE: IRS Collection Advisory approves a request for extension of time to pay. If a section 6324A lien was not previously recorded for the 6166 deferral, Advisory may very likely require that a lien or a bond be filed in order to grant the extension of time to pay the annual installment. The Instructions for Form 4768 are also available on the IRS website.

The Internal Revenue Manual (IRM) is available, with most of the Parts from 1 through 39. Part 4.25.1 contains detailed instructions for field examinations of estate tax returns, and Part 4.25.2 contains detailed processing instructions for Cincinnati Campus personnel who handle estate tax returns, including section 6166 deferral cases.

A page captioned SOI Tax Stats has links to various articles and analyses of estate and gift tax return filings.