HP Printer Error Code 16 — What It Means & How to Fix It

What Does This Error Mean?

Error 16 on an HP printer means the toner cartridge is low or empty. The printer detected that the toner level has dropped below the threshold for reliable printing. You may still get some pages printed, but print quality will start to fade. The fix is to replace the toner cartridge — or on some models, you can temporarily redistribute the remaining toner for a few more pages.

Affected Models

HP LaserJet 4
HP LaserJet 4 Plus
HP LaserJet 5
HP LaserJet 5N
HP LaserJet 5M
HP LaserJet 6L

Common Causes

The toner cartridge has been used and is running low on toner
The toner cartridge is empty and needs to be replaced
A refilled or third-party toner cartridge that the printer cannot accurately read
The toner sensor inside the printer has failed and is giving a false low reading
The toner cartridge is not properly seated and the sensor cannot detect it correctly

How to Fix It

Open the printer's top cover and remove the toner cartridge. Gently rock the cartridge side-to-side 5–6 times to redistribute the remaining toner evenly inside.

This is a well-known temporary fix for HP LaserJet error 16. Redistributing the toner can give you 50–200 additional pages before the cartridge truly runs dry.
Reinsert the cartridge firmly until it clicks or seats securely. Close the printer cover. Try printing a test page.

Sometimes the cartridge was not fully seated, causing the toner sensor to misread. A firm reinsertion can clear error 16 if the cartridge actually has toner remaining.
If print quality is faded, streaky, or uneven after redistributing the toner, the cartridge is genuinely depleted and needs replacement.

Continued printing with a mostly empty cartridge can damage the drum unit in some older HP LaserJet models. Replace the cartridge promptly when output quality drops.
Purchase a replacement toner cartridge. Use genuine HP cartridges for the most reliable results. Third-party and refilled cartridges may also work but can occasionally cause toner sensor errors on older models.

Check the HP compatibility chart or search your printer model number to find the correct cartridge number. Installing the wrong cartridge can damage the printer.
If error 16 returns immediately after installing a new, genuine HP toner cartridge, the toner sensor inside the printer may be dirty or faulty. A technician can clean or replace the sensor.

The toner sensor is a small optical or magnetic sensor inside the toner bay. It can sometimes be cleaned with a dry cotton swab — but access varies by model.

When to Call a Professional

Error 16 is almost always resolved by replacing the toner cartridge yourself. Replacement toner for older HP LaserJet models costs $20–$80 depending on the cartridge. If error 16 persists with a brand-new, genuine HP toner cartridge, the toner sensor may have failed. A technician can replace the sensor for approximately $50–$100.

Frequently Asked Questions

Can I keep printing with error 16 on my HP printer?

Yes, briefly. Remove the cartridge and rock it side to side to redistribute the remaining toner. This can give you 50–200 more pages. But once output quality becomes noticeably faded or streaky, replace the cartridge. Printing on an empty cartridge can cause damage to the drum over time.

Why does error 16 appear on my HP printer with a new cartridge?

If error 16 appears immediately after installing a brand-new genuine HP cartridge, the most likely causes are: the cartridge is not fully seated, the toner sensor inside the printer is dirty or faulty, or the cartridge is for a different printer model. Double-check that the cartridge is the correct model and is firmly installed.

How much toner is left when error 16 appears?

On older HP LaserJet models, error 16 typically appears when about 10–15% of the toner capacity remains. The printer detects that toner is running low and warns you before the cartridge is completely empty. You often have enough for another 100–300 pages depending on what you are printing.