What Toner Does the Brother MFC-9840CDW Use?

by Lauren Elward Last Updated: October 27, 2026

Quick answer: The Brother MFC-9840CDW uses TN110 standard toner (about 2,500 pages black, 1,500 per color) or high-yield TN115 (about 5,000 black, 4,000 per color), plus a DR110CL drum unit rated at about 17,000 pages.

It also has a separate BU100CL belt unit and WT100CL waste toner box. Castle Ink sells compatible TN115 in all four colors and the DR110CL.

CastleScore · October 2026

69/100 — Situational

Brother MFC-9840CDW (Scored on Brother MFC-9840CDW data)

Pillar (weight)	Score	What it is based on
Owner ratings (28%)	—	We couldn't find a retail rating pool for the MFC-9840CDW.
Expert reviews (20%)	—	No published numeric expert score we could verify.
Cost per page (18%)	92	About 1.9¢ per page all-in, blended, with our compatible TN115 toner and DR110CL drum.
Reliability (18%)	68	Most-reported problems: many separate consumables; costly to run; slow two-sided and color output
Features (11%)	76	Print, copy, scan, fax in color, 21 ppm, 50-sheet two-sided document feeder, Wi-Fi, Ethernet and USB.
Value (5%)	—	Not scored without owner ratings

Limited data: We could not find enough owner ratings or published expert scores for this printer, so those weights are spread across the other pillars. With neither owner ratings nor a published expert score, we cap this printer at 69 (Situational) until better data is available.

Discontinued. Brother lists the MFC-9840CDW as discontinued.

CastleScore is Castle Ink’s own editorial rating, built from retailer star ratings, expert reviews, real cost per page and owner complaint patterns, checked October 27, 2026. It is not a customer review. See every ranked printer or how the score works.

The toner, pictured

Our own compatible toner, photographed in-house.

What Toner Does the Brother MFC-9840CDW Take?

Cartridge	Brother part no.	Approx. yield	Castle Ink option
Brother TN115 Black (high yield)	TN115BK	~5,000 pages	Castle Ink TN115BK, $49.95
Brother TN115 Cyan (high yield)	TN115C	~4,000 pages	Castle Ink TN115C, $49.95
Brother TN115 Magenta (high yield)	TN115M	~4,000 pages	Castle Ink TN115M, $49.95
Brother TN115 Yellow (high yield)	TN115Y	~4,000 pages	Castle Ink TN115Y, $49.95
Brother TN110 (standard)	TN110BK/C/M/Y	~2,500 black / ~1,500 color	Amazon
Brother DR110CL drum unit	DR110CL	~17,000 pages	Castle Ink DR110CL, $139.95

Yields are Brother's figures as listed by Brother USA, Staples and 4inkjets. We don't stock the standard TN110; the TN115 costs less per page. Amazon links are tagged (as an Amazon Associate we earn from qualifying purchases).

What Does MFC-9840CDW Toner Cost per Page?

On October 27, 2026, Staples listed Brother's TN110 black at $74.99 and TN115 cyan at $148.99 (out of stock), and Brother's DR110CL at $232.79. With Brother's high-yield toner that's about 3.7¢ a page per color. Our compatible TN115 cartridges are $49.95 each, about 1¢ a page for black and 1.2¢ per color, and our DR110CL is $139.95.

Will Compatible Toner Work?

Yes. Brother printers don't use HP-style dynamic security, and in 2025 Brother publicly denied that its firmware blocks third-party supplies. Brother's warranty doesn't cover damage caused by non-Brother supplies.

How Do I Replace the Toner in the MFC-9840CDW?

Open the front cover and pull out the drum unit until it stops.
Lift out the toner cartridge for the empty color. The cartridges sit in color-coded slots in the drum unit.
Unpack the new cartridge, rock it gently and remove its protective cover.
Drop it into the matching slot, then slide the corona wire cleaner on each slot back and forth if your manual calls for it.
Push the drum unit back in and close the front cover.

These are the standard steps for this type of printer. If your model's door label shows a different order, follow the label.

Which Other Printers Use TN110 and TN115?

The DCP-9040CN, DCP-9045CDN, HL-4040CN, HL-4040CDN, HL-4070CDW, MFC-9440CN and MFC-9450CDN use the same toner and DR110CL drum.

What MFC-9840CDW owners ask

These are the questions that come up most for this printer on retailer Q&A pages, manufacturer support communities and owner reviews, answered in our words.

Should I buy TN110 or TN115?

Both fit. TN110 is standard yield (2,500 black, 1,500 color) and TN115 is high yield (5,000 black, 4,000 color).

Is the drum one unit for all four colors?

Brother sells the DR110CL as a single drum unit rated at about 17,000 pages.

What else wears out?

The BU100CL belt unit and the WT100CL waste toner box are separate replaceable parts.

Can it scan and fax two-sided?

Yes. Its 50-sheet document feeder handles two-sided copying, scanning and faxing.

MFC-9840CDW quirks worth knowing

It prints, copies, scans and faxes in color at up to 21 pages a minute.
It has 802.11b/g Wi-Fi, Ethernet and USB, plus a USB port for printing from a flash drive.
Paper capacity is a 250-sheet tray plus a 50-sheet multipurpose tray, expandable to 800 sheets.
Reviewers found the number of separate consumables made it fiddly and costly to run.

Frequently Asked Questions