The Epson WorkForce WF-7840dtwf uses Epson 812 & 812XL. It takes the same cartridges as the rest of the Epson WorkForce WF-7840 series. Here's every cartridge we carry for it, genuine and compatible, with page yields.
Cartridges that fit
What ink does the Epson WorkForce WF-7840dtwf use?
Epson 812 & 812XL, the same as every Epson WorkForce WF-7840. Standard and high-yield versions fit; high yield costs less per page.
How to check
The model name is on the front of the printer. The letters after the number (dn, dw, fdw) don't change which toner fits. Still unsure? Send us the model and we'll confirm.
More: toner by printer model · find my toner
Related guides
Understanding the Epson 812
What this is
Ink is liquid that an inkjet printer sprays through tiny nozzles. It is great for photos and color, but it can dry out if a printer sits unused for weeks. Print a page every week or two to keep the nozzles clear.
Genuine (also called OEM or original) means made by Epson. It gives the most consistent quality and color, and it is what the manufacturer designs and tests the printer with.
Page yield & cost per page
~300 pages · about 8.3¢ per page
Page yield is how many pages a cartridge prints in the industry-standard test (ISO/IEC 24711). That test prints pages with about 5% coverage, roughly a short business letter. Pages full of photos or dark graphics use more, so your real count may be lower.
Cost per page = price ÷ page yield. It is the fairest way to compare cartridges. High-yield (often marked X or XL) versions usually cost less per page. How yield works
How to install it
- Turn the printer on and open the ink access door. Wait for the carriage to stop.
- Press the tab and remove the empty cartridge.
- Unpack the new cartridge and pull off the plastic tape. Don't touch the copper contacts or nozzles.
- Push it into the slot of the matching color until it clicks.
- Close the door. Let the printer prime and run its alignment page.
Get more pages for your money
- Don't swap at the first "low" warning. Most printers warn early. Keep printing until pages actually fade.
- Use draft or toner-save mode for internal documents and printing you don't need to look sharp.
- Print a little every week or two so ink doesn't dry in the nozzles. Avoid running too many cleaning cycles, which use ink.
- Buy in pairs. Keeping one spare means you never stop mid-job, and larger orders get our volume discount.
Storage & shelf life
Keep spare cartridges sealed in their bag, lying flat, at room temperature and out of direct sunlight. Most are best used within about two years. Check the date on the box. Once opened, install the cartridge right away.
Will it fit my printer?
Match the cartridge number (this one is part number T812320-S) or your exact printer model, found on the front or top of the printer. Models that differ by one letter often take different cartridges.
Toner & ink terms, explained
Page yield
How many pages a cartridge prints in the standard ISO test at about 5% coverage (a short letter). Heavy graphics and photos print fewer pages.
Standard, high yield, XL, XXL
Same printer, different amount of toner or ink. HP marks high yield with X (and A for standard), and Brother and Canon often use H, XL or XXL. Bigger cartridges cost more but less per page.
Cost per page
Cartridge price ÷ page yield. It is the fairest way to compare two cartridges, or two printers' running costs.
Genuine / OEM / original
Made by the printer brand itself. It gives the most consistent results and is what the printer was designed and tested with.
Compatible
A new cartridge made by another company to fit the same printers, usually 30–60% cheaper. Ours carry a 1-year replacement guarantee.
Remanufactured
An original cartridge that was emptied, cleaned, fitted with new worn parts and refilled. It is lower-cost and keeps cartridges out of landfill.
Drum unit
The laser printer part that transfers toner to paper. On many printers, especially Brother, it is separate from the toner and lasts through several toner cartridges.
Toner vs ink
Toner is a dry powder used by laser printers and never dries out. Ink is liquid used by inkjets, better for photos, but it can dry out if unused. More
Cartridge number vs part number
The cartridge number (like 58A or TN760) is the short name on the box. The part number (like CF258A) is the exact code. Both identify the same item. Match either one to your old cartridge.
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