HP 45 Ink Cartridges – 51645A Black, MICR & Pigment Colors

Castle Ink sells remanufactured HP 45 ink cartridges in every size HP makes: HP 45 black (51645A), a 45 black MICR cartridge for check printing, and HP 45-style pigment cartridges in dark black, red, blue, green, orange, purple, pink, yellow and brown for Accufast, Buskro, Secap and other addressing systems. They fit the HP DeskJet 710c, 720c, 820c, 830c, 850c, 870c, 880c, 890c, 895c, 930c, 932c, 950c, 952c, 960c, 970c, 980c, 990c, 1100c, 1120c, 1180c, 1220c, 1280 and 1600c, the OfficeJet G55, G85, G95, K60, K80, R40, R60, R80 and T45, the Photosmart 1000, 1100, 1115, 1215, 1218 and P1000, the DesignJet 700, 750c and ColorPro, and many addressing and labeling printers that take the 45 cartridge. Each cartridge is a remanufactured original HP shell, refilled and tested in the U.S. Orders placed by 4 PM ET ship the same business day, shipping is free over $50, and every cartridge is covered by our 1-year 100% satisfaction guarantee.

Firmware note: keep automatic firmware updates turned off on your printer so a future update can't block third-party cartridges. If the printer shows a “non-genuine ink” message, choose Continue or OK; printing is not blocked. Printing checks? Choose the MICR black version.

Not sure which cartridge your printer takes? Use our Find Ink by Printer lookup.

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HP 45 Ink: Common Questions

Is there a high-yield version of HP 45?

HP 45 black prints about 930 pages; HP made only one size, so there is no XL to choose. The pigment color versions are made for industrial addressing printers and are not for the home DeskJets listed above.

Which printers use HP 45 ink?

HP DeskJet 710c, 720c, 820c, 830c, 850c, 870c, 880c, 890c, 895c, 930c, 932c, 950c, 952c, 960c, 970c, 980c, 990c, 1100c, 1120c, 1220c, 1280, OfficeJet G55, G85, K60, K80, R40, R80, T45, Photosmart 1000, 1100, 1115, 1215, 1218, P1000. Our Find Ink by Printer page has a guide for each model.

Will remanufactured HP 45 cartridges work in my printer?

Yes. These printers predate HP+ and HP's cartridge-blocking firmware, so a remanufactured cartridge installs and prints like an original. If the printer shows a non-genuine-ink message, choose OK or Continue. If a cartridge from us still isn't recognized, contact us and we'll replace or refund it under our 1-year guarantee.

Which HP 45 should I buy?

The standard 45 black for any of the DeskJet, OfficeJet or Photosmart models above. The MICR version is only for printing checks. The pigment colors are for addressing and labeling systems (Accufast, Buskro, Secap, Rena and similar) that take the 45 body; they are not for home printers. Ink keeps for about two years sealed, so stocking up is safe.

More help: All HP ink cartridges · Find ink by printer. Updated October 2026 by William Elward, founder of Castle Ink (in business since 2005).