HP Printer Error Code 34 — What It Means & How to Fix It

What Does This Error Mean?

Error 34 means the printer loaded a different paper size than what the print job is asking for. The printer detects a mismatch between the paper in the tray and the paper size set in the document. This is an easy fix — usually just a settings adjustment.

Affected Models

HP LaserJet Pro M200 Series
HP LaserJet Pro M400 Series
HP LaserJet Enterprise M600 Series
HP Color LaserJet Pro M454
HP LaserJet Pro MFP M428

Common Causes

The paper loaded in the tray is a different size than what the document specifies
The tray size setting in the printer menu does not match the physical paper loaded
The print driver on your computer has a different default paper size than your printer's tray
Custom or non-standard paper size is loaded but the printer is set to expect Letter or A4
The paper guides in the tray are not snug against the paper, confusing the printer's sensor

How to Fix It

Look at the paper in the tray. Confirm what size it is — Letter (8.5 x 11), A4, Legal, etc.

Remove the paper stack and check the label on the ream if you are unsure of the size.
On the printer's control panel, go to the tray settings and set the tray paper size to match what is physically loaded.

On touchscreen models, go to Setup > Paper Setup > Tray 1 > Paper Size and select the correct size.
On your computer, open the document you were trying to print. Check that the paper size in the document's page setup matches the paper in the printer.

In Microsoft Word, go to Layout > Size to see and change the page size.
Open the print dialog on your computer and confirm the paper size setting in the printer preferences also matches.

There can be three separate places where paper size is set — the document, the print dialog, and the printer's tray. All three need to match.
Adjust the paper guides in the tray so they rest snugly against the edges of the paper stack, then retry the print job.

Loose guides can make the printer think a different paper size is loaded, even when it is correct.

When to Call a Professional

If error 34 keeps appearing even after you confirm the paper size matches in all settings, the paper size sensor or tray detection mechanism may be faulty. A service technician can test and replace the sensor. Repair typically costs $80 to $150 depending on the printer model.

Frequently Asked Questions

Why does my HP printer keep showing error 34 even after I change the paper size?

There may be a conflict between the paper size set in the print driver and the tray setting on the printer itself. Check both places — the tray setting on the printer's control panel AND the paper size in your computer's print preferences. Both need to match the paper physically in the tray.

Does error 34 damage the printer?

No. Error 34 is just a paper size mismatch warning. The printer stops and waits rather than printing on the wrong paper. It will not damage any components.

Can I make my HP printer ignore paper size mismatches?

Some HP printers have an 'Override' or 'Continue' option in the paper mismatch settings. This lets the printer print on whatever paper is loaded, even if sizes don't match. Go to Setup > Paper Setup and look for a mismatch override option. Use this carefully — your printout may be cut off if the paper is smaller than the document.