Faxing Form 5472: Which Send-Dialog Settings to Enable (and Why HD Is a Trap)

The Send Dialog Has More Options Than You Need — Here's What to Touch

When you click Send on fax.plus, a gear icon opens an options panel with a dozen toggles. Most of them are tempting and most of them are wrong for an IRS fax. The two that actually matter — auto retry on failure and auto resume on partial send — should be on. Everything else should be off, and the reason is the same in every case: the IRS fax line behaves like a government line, and government lines reject anything unusual.

Schedule Transmission — Off

Don't schedule the fax for later. You want immediate feedback on whether it transmitted successfully. A scheduled send leaves you waiting overnight only to discover the next morning it failed at 3 AM and you have to start over. Unless you have a specific reason to delay (almost no one does for an IRS filing), send it now and watch it land.

Auto Retry on Failure — On (3 retries, 5 minutes apart)

The IRS line gets busy, especially around quarterly deadlines. A first attempt that fails is usually a transient busy signal, not a permanent problem. Set auto retry to 3 attempts with 5-minute intervals. The service handles the retry loop in the background and shows you the final outcome. Most failures resolve on retry one or two.

Auto Resume on Partial Send — On

If the connection drops mid-transmission (rare but happens), auto resume picks up from where it left off instead of restarting from page 1. Without this, a 5-page package that drops on page 4 sends pages 1–4 once, then pages 1–5 again, and the IRS receives a duplicate that confuses processing. Always on.

Fax to Human-Operated Telefax — Off

This setting routes the fax through a human operator on the receiving end. IRS fax numbers are machine-receiving lines, not staffed answer points. There's nobody on duty to pick up — especially across time zones — so this option silently increases failure rate. Off.

Email Receiving PDF of the Fax — Off

The IRS doesn't accept this. The setting is for situations where you fax a company that also wants the file by email — adds the extra channel automatically. The IRS only reads the fax, never the email, so adding the email just introduces an unusual element. Stick to standard.

Send as High-Definition (HD) Fax — Off (This One Surprises People)

This is the counterintuitive one. The IRS says they want 300+ DPI, so HD looks like the right choice. It isn't. HD fax uses an extended fax protocol that some older receiving systems — including, by all accounts, the IRS receiving system — don't fully support. An HD fax to an older receiver can drop, garble, or arrive blank.

The plain black-and-white standard fax is ironically safer here. Your source PDF is already 300 DPI (from flatten or image export), and the standard fax mode delivers it cleanly. HD doesn't get you any more revenue, just more risk.

The Pattern: Don't Introduce Anything Unusual

The unifying rule across all these settings is: don't introduce anything unusual. The IRS processing center handles thousands of faxes a day on standard equipment. Anything non-standard increases the chance a human has to manually intervene, and human intervention means weeks of delay. Boring is safer. Click save on the two settings you turned on, leave everything else off, and click Send.

Fax Is Not Email — Allow Five Minutes

Fax transmits at about one page per minute. A 5-page IRS package takes roughly five minutes to fully transmit. Don't refresh the dashboard every 10 seconds expecting an instant result — you'll panic. Go check the outbox in five minutes; the status should have moved from "sending" to "delivered." The dashboard shows the date and timestamp, which is your proof of timely filing. Some careful clients screen-record the entire transmission — that's also fine. The more proof you keep, the more defensible the filing is.