If an office expects to spend about $50 or more on routine postage in a month, then a postage meter is definitely beneficial. The postal charge is printed by the meter unit of the equipment. In the case of online postage, there are services that permit the customer to download the postage from the Internet and print it directly onto the envelope or labels using the existing printer. This is either software based or integrated with a mini-hardware storage device.

The postage meter uses a homogeneous ink for printing the indicia. This ink is formulated by dissolving a coloring material made of a fluorescent toner in a non-volatile blending solution consisting of low molecular weight, fluid, and nonionic surfactants. The surfactants are organic solutions of alcohol or ester and glycols. The consistency of the ink can be altered using viscosity modifiers. All the components of the ink are non-toxic, non-hygroscopic, and do not affect the material on which they are used.

The colors of ink used for printing postage meter stamps are red, blue, purple, green, black, orange, and lilac. According to the United States Postal Service (USPS) customer support for mailing standards for meters used in post offices, only tape and red ink furnished by the Postal Service may be used. Post offices are required to use the green ink in meters, while customers should never use red ink. They may use other colors as long as the ink meets the Postal Service's fluorescent requirements. Of late, inks using components for both fluorescence and phosphorescence have been patented.

The printers generally use different ink cartridges, so it is important to be aware of the specific cartridges for replacement. The lifespan of the ink cartridges depends upon the extent of use; with this in mind, they may be bought in bulk from the manufacturers. Compatible cartridges and recycled and remanufactured cartridges may be purchased from other manufacturers to suit several models of printers. Generally, offices always take stock of the needs of the quantity of ink or the cartridges before placing the purchase order.