A POS system buying guide for owners who hate surprises.

The most important question when buying a POS system is whether it is open, meaning it works with more than one payment processor, or closed, meaning it only works with the processor that sells it. After that, compare the full monthly cost, including software, hardware and processing, and test the system with your own products and staff before you sign.

A point-of-sale (POS) system runs your checkout: products or menu, prices, taxes, discounts, staff, tips, inventory and reports. It touches every sale, so a poor choice costs you every day. Here is how to choose carefully.

Open vs. closed systems

This is the decision that matters most, because it controls how easy it is to change processors later.

	Open system	Closed system
Processors	Works with several	Works with one, usually the seller
Processing rates	Can be shopped and negotiated	Set by the system provider
Switching processors	Usually a settings change	Often means replacing the whole system
Hardware	Often works with several terminal brands	Usually proprietary devices
Upside	Flexibility and leverage	One company for everything

A closed system can be simple to start with, but if its processing becomes expensive, your only way out may be to buy a new system and retrain staff. That is a strong reason to look hard at open options. If you already have a closed system, read the switching processors checklist before deciding anything.

Features to check for your type of business

Every POS covers basic sales. The differences show up in the details your business depends on:

• Restaurants: table maps, coursing, kitchen printers or screens, modifiers, split checks, tips and tip adjust, online ordering.
• Retail: barcode scanning, inventory counts, variants such as size and color, purchase orders, returns and exchanges.
• Grocery and convenience: fast lanes, scales, age checks, high item counts and quick price changes.
• Service businesses: appointments, deposits, customer records and invoicing.
• Multi-location: central menus or catalogs, combined reports and one login across stores.

Write your must-haves down before any demo. Sales demos tend to show the features that look good, not the ones you need on a Friday night.

Look beyond the register, too. Many owners only discover after buying that the POS doesn’t connect to their accounting software, online store or gift card program, so someone ends up retyping totals every night. Ask which integrations exist today, not which are “on the roadmap”. And ask who owns your data. Your sales history, product list and customer records should be yours to export if you ever leave, in a format another system can read. A system that keeps your data locked inside makes leaving painful, even when it should be easy.

The true monthly cost

POS pricing comes in pieces. Add them up for a full year before comparing:

1. Software subscription, often per location, per station or per feature tier.
2. Hardware, bought, rented or leased: stations, terminals, printers, cash drawers, scanners and kitchen screens.
3. Processing, which is often the largest cost over time. Ask whether it is Interchange-Plus, tiered or flat-rate, and whether the system lets you choose your processor.
4. Add-ons, such as online ordering, loyalty, gift cards or advanced reporting.
5. Setup and support, including menu or product entry, training and after-hours help.

A low software price can hide high processing costs, and the reverse. Our guide on Interchange-Plus vs. flat-rate vs. tiered pricing explains how to compare processing fairly.

Read the contract for early termination fees, automatic renewals and equipment leases. A POS deal can include several agreements: software, processing and equipment. Ask for all of them before you sign.

Questions to ask every POS seller

• Can I use a processor of my choice, or only yours?
• If I leave, can I keep the hardware, and will it work with another system?
• Can I export my sales, product and customer data in a standard format?
• Is there an early termination fee on the software, the processing or the equipment?
• Who answers the phone when the system goes down at 7 p.m. on a Saturday?
• Does it support chip and tap, and can it run surcharging or a cash discount program correctly if I want one?
• Does it connect to my accounting software, online store or payment gateway?

Answers in writing are worth more than answers in a demo. If a seller won’t say whether you can change processors, assume you can’t.

Testing before you commit

Ask for a trial or a sandbox with your own products or menu loaded. Have the people who will use it every day ring up real orders, process returns and close out the day. Time how long common tasks take. Try it on your actual internet connection and at your busiest station. Check what reports look like at the end of the day and whether your bookkeeper can use them. For simpler setups, a countertop terminal may be all you need. Compare formats in countertop vs. mobile vs. POS.

What PayZoom does

We don’t sell proprietary POS. We are platform-agnostic, so we fit your existing POS when it works for you and help you compare options when it doesn’t. PayZoom hardware includes the PAYS POS, a dual-screen countertop POS with a cash drawer for a complete checkout lane, and the Dejavoo P18, a countertop tablet POS for counters, cafés and retail floors. We work with open and closed architecture systems, recommend Interchange-Plus processing, charge no early termination fees, and a real person answers when you call. See also how to choose a card terminal.