How to Find the Right Franking Ink Cartridge for Your Machine
To find the right franking ink cartridge, match it to your exact franking machine make and model, then check whether your machine franks in red or blue. Older standard machines use Royal Mail approved red ink, while Smart and Mailmark machines use approved blue ink. Buying the cartridge listed for your specific model is the safest way to guarantee a crisp, scannable frank and to avoid rejected mail.
Franking ink looks simple until you go to reorder and realise there are dozens of cartridges, each tied to a particular machine. Choose the wrong one and you either cannot fit it, or your impressions come out faded and get returned. This guide walks you through picking the correct cartridge first time, whether you run a compact desktop unit or a high volume mailroom machine.
Why franking ink is not interchangeable
Franking machines use specialised ink that Royal Mail has tested through its automated sorting centres. The ink is formulated so the postal mark, and the 2D barcode on Mailmark franks, can be read quickly and accurately by scanning equipment. This is why you cannot simply refill a cartridge with generic printer ink or move a cartridge between different machine families.
Each manufacturer designs its cartridges around a specific printhead and a specific machine range. A cartridge built for a compact Pitney Bowes desktop machine will not physically fit or function in a large FP Mailing mailroom unit, even though both put ink on an envelope. That is why our store is organised by machine, so you can go straight to the cartridges and labels for your model without guesswork.
Step one: identify your machine make and model
Start with the brand. The UK market is dominated by a handful of manufacturers: Pitney Bowes, FP Mailing, Frama, and Quadient (formerly Neopost). Your machine will carry the brand name on the front, and the model number is usually printed on the front panel, on a label underneath, or shown in the settings menu on the display.
Once you have the brand, note the exact model. Ranges such as the Pitney Bowes DM series, the FP Mailing Postbase series, the Frama Matrix series and the Quadient IS and IN series each split into several models, and the cartridge can differ between them. Writing down the full name, for example "FP Mailing Postbase Qi6" rather than just "Postbase", saves time and prevents ordering errors.
Step two: match the cartridge to that exact model
With your make and model in hand, find the matching collection. We group every cartridge and label set by machine so the fit is guaranteed. For example, Quadient and Neopost owners can browse the Neopost IS series ink and labels, Pitney Bowes users can find the DM60 and K722 cartridges, and Frama customers can head to the Frama Matrix range.
If your model has been renamed over the years, do not worry. Neopost machines are now sold under the Quadient brand, but the cartridges are the same, so the older model number is still the one to search for. When in doubt, our team can confirm the correct cartridge for you through the contact page.
Red ink or blue ink: check which your machine needs
One detail catches people out. Royal Mail approved franking ink comes in two colours, and they are not interchangeable. Older standard franking machines use red ink, while newer Smart and Mailmark machines use blue ink. The switch to blue supports Royal Mail's sorting machines, which read a blue franked mark more accurately, and it also helps prevent fraud.
The good news is that each cartridge in the correct model collection is already the right colour for that machine, so as long as you buy the cartridge listed for your model, the colour takes care of itself. If you have recently upgraded to a Mailmark machine, remember that your old red cartridges will not work in it.
Original or compatible: which to choose
Most machines can run either an original manufacturer cartridge or a quality compatible one. Compatibles are typically cheaper and, when made to the correct specification, produce a fully approved and scannable frank. Originals carry the manufacturer badge and sometimes a longer warranty. We cover the trade offs in detail in our guide to original versus compatible franking ink, which is worth a read before you decide.
Do not forget franking labels
If you frank parcels or thicker packets that will not feed through the machine, you will need self adhesive franking labels as well as ink. Every model collection lists the correct labels alongside the cartridges, and you can learn when they are needed in our guide to franking machine labels. If you also send letters in bulk, our range of envelopes pairs neatly with your ink order.
Keep your prints crisp once the cartridge is fitted
Buying the right cartridge is half the job; storing and using it well is the other half. Ink dries out if a cartridge is left unsealed or kept in a cold, damp place, so keep spares in their packaging until needed. Our article on how long franking ink lasts explains shelf life and storage in full. If your impressions ever look patchy, our guide to faded franking covers the common causes and fixes.
Frequently asked questions
How do I know which franking ink cartridge fits my machine?
Identify your machine's brand and exact model number, usually printed on the front panel or in the settings menu, then buy the cartridge listed in the collection for that specific model. Matching to the exact model guarantees the cartridge fits and franks correctly.
Can I use red ink in a Mailmark franking machine?
No. Smart and Mailmark franking machines require Royal Mail approved blue ink, while older standard machines use red ink. Buying the cartridge listed for your model ensures you get the correct colour automatically.
Is compatible franking ink as good as the original?
A quality compatible cartridge made to the correct specification produces a fully approved, scannable frank and usually costs less than an original. The main differences are the brand badge and, in some cases, the warranty length.
Will the wrong cartridge cause my mail to be rejected?
Yes, it can. A cartridge that does not match your machine may not fit at all, or it may print faded or unreadable franks that Royal Mail cannot scan, which can lead to mail being delayed or returned. Always match the cartridge to your exact model.
Do Neopost and Quadient machines use the same ink?
Yes. Quadient is the current brand name for machines previously sold as Neopost, and the cartridges are unchanged, so you can search using your original model number and order with confidence.
Ready to reorder? Browse the cartridge and label collection that matches your machine and get a crisp, Royal Mail ready frank every time. If you are unsure which cartridge you need, get in touch with our team and we will point you to the right one.