It's official: Here's how the IRS will contact you if you are late with a deposit.

When the IRS first announced that it would phone even slightly late employment tax depositors as soon as 48 hours after a missed payment or filing and follow up with a visit, many small businesses complained that it would be extremely difficult to tell an IRS phone call from that of a scammer.

Now the IRS Small Business/Self-employed Division has issued a memorandum to revenue officers with the rules for contacting taxpayers under the tax deposit alert (TDA) program.

The new rules: Although a personal visit (*field contact*) is the preferred method under TDA, when this is not possible or practical, the IRS will send you a letter saying that a revenue officer will phone you; you should receive the call within 15 days. But the written notice must be sent only before the first phone call. If additional contacts are needed, phone calls can be made without a prior written notice.

The system is expected to be fully rolled out early in 2017, but will be phased in and tested in 2016. Initially, the IRS planned to let revenue officers contact the businesses in whichever manner might be more effective for that taxpayer: email, regular mail, telephone call, or personal visit. (SBSE-05-0716-0035)