Some practitioners go to the trouble of obtaining a "proof of mailing" from the post office when mailing important matters to the IRS. Other practitioners insist on registered mail. Who's most correct? It depends on what circuit the taxpayer lives in. The Second and Sixth Circuits would require registered mail to establish delivery to the IRS. The Eighth and Ninth would not. The importance of the difference is emphasized by a recent Sixth Circuit case, in which the court reaffirmed its rejection of the common law "mailbox rule."

The court held that the mailbox rule is overridden by I.R.C. sec. 7502. Under the mailbox rule, proof of mailing of a properly addressed communication bearing proper postage raises a rebuttable presumption that the communication was received in due course. Section 7502, on the other hand, says that a communication mailed on or before a filing date and delivered after the date will be deemed timely filed if it bears a postmark not later than the filing date. Section 7502 goes on to state that registered mail that is registered on or before the filing date is prima facie evidence of delivery to the IRS.

In the recent case, the taxpayer had signed and mailed an S corporation election form 54 days before it was due. But the IRS claimed it never received the form. In the Eighth and Ninth Circuits, the application of the mailbox rule would mean that the election had been properly filed. But the Sixth Circuit reaffirmed that in its area, the taxpayers needed to use registered mail. The S corporation election was, therefore, invalid.

Getting back to the original question, which practitioner's approach is best? Although proof of mailing may be sufficient in some parts of the country, clearly the most prudent approach is to send important communications to the IRS using registered mail, return receipt requested. A holding of prima facie evidence is nice to have on your side. A good office practice if this approach is used is to have the type of communication, for instance the form number, typed in the margin of the green return receipt card.