"Works with your existing POS" is one of the most common promises in payment sales, and one of the least explained. Most businesses hear it and assume a technician will somehow make a new system talk to the old one. In practice it means something more specific, and more useful: you keep the POS software you already run, and only the payment leg changes.
Two ways a card payment can touch your POS
In a fully integrated setup, the POS application itself handles the card data and passes it to the processor. The terminal is a peripheral of the software. It is also why those systems carry a heavy compliance burden: the POS, the local network, and every server it touches sit inside the cardholder data environment.
In a semi-integrated setup, the payment terminal handles the card data on its own and talks to the processor directly. The POS still drives the sale (sends the amount, gets the approval, prints the receipt, closes the check), but the card number never passes through the POS application. The two systems exchange a result, not a card. That distinction is the whole game.
Semi-integrated is the pragmatic path
For a business already running Aloha, Micros, or any established POS, semi-integrated processing is almost always the right answer. You do not replace the software, so workflows, menu programming, and reporting all stay. The card data is isolated to a hardened, purpose built device instead of spreading across your network. And the terminal can be deployed onto a legacy environment without rebuilding it, which is what makes a clean cutover possible.
This is the architecture behind deploying PAX terminals onto an existing Oracle Micros or Aloha floor, processing through Global Payments, without touching the POS software itself.
What P2PE buys you
The reason the terminal can isolate the card is point to point encryption. The card is encrypted the moment it is read, inside the device, using keys the merchant never holds. From there, the data in transit is ciphertext. The POS, the local network, and the back office servers never see a usable card number, because they never receive one.
The PCI scope reduction is the real win
Under PCI DSS 4.0, your scope is defined by where cardholder data lives, flows, and is processed. In a fully integrated POS, that scope includes the application and much of the infrastructure around it. With semi-integrated P2PE, the cardholder data environment shrinks to the terminal, and the POS is out of the PAN flow. For a multi location operator, that is the difference between an audit that spans the whole estate and one scoped to a managed, validated device.
What changes, and what stays yours
Stays yours: the POS software, the menu, the workflows, the reporting, the hardware you are happy with. Changes: the payment terminal, the encryption, and the processing relationship through Global Payments. Optional: the platform underneath, on your timeline, never a precondition for taking payments.
That is the difference between selling you a new system and processing what you already have. The first asks you to start over. The second asks you to change one leg and leave the business running.