Printers & scanners

Printer shows a paper size mismatch error

A paper size mismatch error means the size selected in the print settings doesn't match what the printer detects loaded in the tray.

Difficulty
Easy
Time
5–15 minutes
DIY cost
$0
Pro cost
$60–$100

Symptoms

  • Error like 'Load Letter Paper' or 'Paper Size Mismatch'
  • Printer pauses mid-job waiting for the correct size
  • Error persists even after loading the requested size
  • Different trays hold different paper sizes

Likely causes

  • CommonPrint job requesting a different paper size than what's loadedThe document or print settings specify one size, like Legal, while the tray has another, like Letter.
  • CommonPaper tray's size guides set incorrectlySome printers detect paper size based on the physical position of adjustable guides in the tray.
  • PossibleWrong tray selected in the print job for multi-tray printersOn printers with multiple trays, the job might be pulling from a tray with a different size loaded.

What to do

  1. Check the print dialog's paper size setting and confirm it matches the paper physically loaded in the tray.
  2. Adjust the paper tray's width and length guides to snugly match the actual paper size loaded, since misaligned guides can cause incorrect size detection.
  3. If your printer has multiple trays, confirm the print job is set to pull from the tray containing the correct size.
  4. Reload the requested paper size if you want to proceed with the original settings.
  5. Alternatively, change the print job's paper size setting to match what's already loaded if that's more convenient.
  6. Restart the print job after correcting either the settings or the paper to clear the mismatch error.

Tools and parts

  • None

When to call a pro

This is a settings/loading issue rather than a hardware fault; if the error persists despite correctly loaded paper and matching settings, the tray's size-sensing mechanism may need professional inspection.

Safety

Generally low risk

Generally low risk for a careful person. Stop if anything looks different from what this guide describes.

Related guides

Operator provides AI-generated troubleshooting information. It can be wrong. For safety-critical, electrical, gas, structural, medical, automotive safety, or other high-risk problems, consult a qualified professional.