What does "Communication Error" mean on a fax machine?

A communication error means the sending and receiving fax machines lost their connection during transmission. Common causes include poor phone line quality, VoIP interference, or the remote machine hanging up. Lower your baud rate to 9600, check your phone line for static, and retry. See our [fax troubleshooting guide](/blog/fax-not-going-through/) for more fixes.

What does "NG" mean on a fax report?

NG stands for "No Good" — it means the fax transmission failed. Check the error code next to it for the specific cause (busy line, communication error, no answer). If no code is shown, the most common causes are a bad phone line or an incompatible remote machine.

Why does my fax keep failing with error 344?

Error 344 means the remote fax machine stopped responding during transmission. This is usually caused by a poor phone line, a VoIP connection issue, or the remote machine running out of paper or memory. Retry after 5 minutes. If it persists, ask the recipient to check their machine.

How do I fix ECM errors on my fax machine?

ECM (Error Correction Mode) errors usually happen on noisy phone lines or VoIP connections. The fix is to turn ECM off in your fax machine's settings (usually under Fax Settings > ECM). This stops the retransmission loops that cause timeouts. On a clean analog line, you can leave ECM on.

Can I avoid fax errors entirely?

The most reliable way to avoid fax errors is to use an online fax service like [mFax](https://mfax.to). Online fax bypasses phone lines entirely, so you never deal with busy signals, line noise, or ECM conflicts. mFax delivers faxes with a 98% success rate.

Fax Error Codes Explained: Common Errors & How to Fix Them

Seeing an error code on your fax machine? This guide explains every common fax error code — from communication errors and busy signals to ECM failures — with the exact fix for each one.

Frequently Asked Questions

What does "Communication Error" mean on a fax machine?: A communication error means the sending and receiving fax machines lost their connection during transmission. Common causes include poor phone line quality, VoIP interference, or the remote machine hanging up. Lower your baud rate to 9600, check your phone line for static, and retry. See our [fax troubleshooting guide](/blog/fax-not-going-through/) for more fixes.
What does "NG" mean on a fax report?: NG stands for "No Good" — it means the fax transmission failed. Check the error code next to it for the specific cause (busy line, communication error, no answer). If no code is shown, the most common causes are a bad phone line or an incompatible remote machine.
Why does my fax keep failing with error 344?: Error 344 means the remote fax machine stopped responding during transmission. This is usually caused by a poor phone line, a VoIP connection issue, or the remote machine running out of paper or memory. Retry after 5 minutes. If it persists, ask the recipient to check their machine.
How do I fix ECM errors on my fax machine?: ECM (Error Correction Mode) errors usually happen on noisy phone lines or VoIP connections. The fix is to turn ECM off in your fax machine's settings (usually under Fax Settings > ECM). This stops the retransmission loops that cause timeouts. On a clean analog line, you can leave ECM on.
Can I avoid fax errors entirely?: The most reliable way to avoid fax errors is to use an online fax service like [mFax](https://mfax.to). Online fax bypasses phone lines entirely, so you never deal with busy signals, line noise, or ECM conflicts. mFax delivers faxes with a 98% success rate.