Which ink does the HP OfficeJet Pro 8620 use?

The HP OfficeJet Pro 8620 uses the HP 950 and 951 pairing, where the black is a 950 and the colours are 951. That trips people up at the checkout, because an order of four 950 cartridges is four blacks. Our listing holds the standard HP 950 black plus the high yield HP 950XL black and the three HP 951XL colours.

For a machine from 2013 the running costs are still good. The 950XL black is rated at 2300 pages and lists near $42, about 1.83 cents a page, against 2.8 cents for the standard 950 black at 1000 pages and $28. Each 951XL colour is rated at 1500 pages for around $30, about 2.0 cents, so a page carrying all four inks comes to roughly 7.83 cents. The catch on a machine of this vintage is the hardware rather than the ink, since the printer has been wearing out for over a decade while the cartridges are new.

The age of this machine is misleading about firmware. HP puts the OfficeJet Pro 8620 on the list of inkjets its cartridge blocking firmware reached, so a compatible 950 or 951 can be refused after an update even on a printer of this vintage, and the store page for the 8620 says nothing about it. HP publishes removal firmware for this model whatever date the unit was built. Supply still favours the compatible either way: genuine stock has been sitting in warehouses for years, while compatibles are still being manufactured and turned over.

The print head on this model lives in the printer rather than in the cartridge, and it is the part most likely to fail after a decade. That changes the order of diagnosis. If a colour goes missing, a fresh cartridge is not the answer until a nozzle check says the channel is clear, and a printhead problem message names the exact part that has given up. If rows of missing colour survive two cleaning cycles, the head is the part that has failed and a fresh cartridge will print exactly the same page.

A quirk of timing hangs over the supply here. HP launched the 8620 in 2013, and 2013 is also the last year any machine we track was designed for the 950 and 951 numbers, so this printer arrived just as its own cartridge family stopped growing. Twenty printers in our catalogue share that pattern, launched in 2013 or later onto a number nothing newer ever used. It rarely means shortage, but it is why the discontinuation guide further down is built around the cartridge number instead of the printer's age.