Can I refill HP ink cartridges?

Indeed, you can. In any case, it relies upon which one. Some ink cartridges can be topped off. In any case, Hp utilizes some tech to screen the ink (they compose the information, I mean, the ink level in the chip thus when the ink is running which means the chip saying it is running out.) and if the printer can demonstrate the ink level legitimately, regardless of whether you have done the topping off, the printer would in any case caution you that it is out of ink.