Fax Troubleshooting: Why Your Fax Failed and How to Fix It (2025)

If your fax failed, don’t panic. Most issues come down to number formatting, destination device status, or document quality. Here’s a quick, practical checklist.

Quick Fix Checklist (2 Minutes)

• Re-enter the number in international format (e.g., +1 212 555 0123)
• Remove leading zeros from international area codes
• Resave as PDF and ensure black text on white
• Try during recipient business hours
• Send a 1‑page test first

See basics: How to Send a Fax Online

Common Error Causes

• Busy destination line: Try again or call ahead
• Invalid number format: Use +[country] [area] [local]
• Poor quality scans: Rescan at 300 DPI, high contrast
• Large files: Compress PDF below 10–15 MB
• Recipient issues: Out of paper, unplugged, or off-hours auto-shutdown

International Gotchas

• Always begin with ‘+’ and the country code
• Drop leading ‘0’ from area codes (e.g., UK 020 → +44 20)
• Verify country code here: Country Codes List

When to Switch Methods

• Court deadlines today? Fax and send certified mail as backup
• Medical emergencies? Fax and call to confirm receipt
• Repeated failures? Try a different destination number or contact support

Keep Proof

Save your delivery confirmation email or PDF receipt. It’s your evidence for courts, insurers, and business records.