How to take in-person payments with Square
You don’t need a $299 terminal to sell in person. Sync your inventory to Square, take payment on the phone in your pocket with Tap to Pay (or a cheap reader), and let every sale flow back into ResaleOS on its own — stock decremented, item delisted everywhere else. Here’s the whole setup, start to finish.
Two POS paths, one that needs no hardware
This guide covers the phone-only path: sell in Square’s app and reconcile into ResaleOS. If you’d rather check out inside ResaleOS with a countertop reader, ResaleOS also supports a paired Square Terminal or Stripe Terminal — that path uses hardware. Pick phone-only to start for free.
Connect Square as a sales channel
From the dashboard, go to Settings → Sales channels → Square and click Connect with Square. You’ll approve access in Square, then land back in ResaleOS. Finish by mapping your ResaleOS location to a Square location so inventory syncs to the right place.
Square
Catalog sync · sales import · POS reconciliation
Push your products to Square
Publish your items to Square. Each product becomes a Square catalog item, carrying its title, price, SKU, quantity, and photos. This is the step that makes real in-person selling work — you’ll ring these items up by name at checkout.
Tip: keep ResaleOS as your source of truth. It pushes stock to Square and pulls sales back, so the two systems stay in agreement instead of drifting apart.
Get your phone ready to tap
Install the free Square Point of Sale app and sign into the same Square account. Then choose how you’ll take the card — none of these is the expensive terminal.
Tap to Pay
$0 — no hardwareTurn it on in the app. iPhone XS+ or Android 9+ with NFC. Takes contactless cards, Apple Pay, and Google Pay.
Contactless + chip reader
~$59A small Bluetooth reader for physical tap and chip cards. Add it only if customers still hand you a card.
Magstripe reader
$10 (first free)Swipe-only. A cheap fallback — most phone-first sellers won’t need it.
Ring up the item and take payment
In the Square app, search your synced product by name or SKU, add it to the cart, and have the customer tap their card or phone. Selling the catalog item — not a custom amount — is what puts the item on the receipt and carries the SKU back to ResaleOS.
Let the sale reconcile in ResaleOS
You don’t have to do anything here. As soon as the payment completes, Square notifies ResaleOS, which records the sale against that exact item, decrements its stock, and delists it from every other channel it was live on.
Sales normally import on their own within moments. If you ever need to backfill, you can also import sales from Square manually from the Sales screen.
The details that trip people up
Ring up the catalog item, not a custom amount
Always add the synced product to the cart rather than typing a custom dollar amount. Only a catalog item carries the SKU that lets ResaleOS match the sale back to the right product, decrement its stock, and delist it elsewhere. A custom amount tracks nothing.
Which phones support Tap to Pay?
An iPhone XS or newer on a current version of iOS, or most Android phones running Android 9 or later with NFC. No dongle or reader is needed on either — the phone is the reader.
What does it cost?
Square’s free plan has no monthly fee, and Tap to Pay costs nothing to switch on. You pay Square’s standard in-person rate per tap — the same rate a $299 terminal charges. Confirm the current number on Square’s pricing page, as rates change.
Prefer a countertop reader inside ResaleOS?
You can. ResaleOS’s built-in POS checkout drives a paired Square Terminal or Stripe Terminal for hardware-based, in-app checkout. The phone-only path in this guide uses Square’s own app instead, so you can start with no hardware at all.
- How to take card payments on your phone without an expensive terminal — the background, the fees, and the alternatives.
- How auto-delisting works — what happens across your channels the moment an item sells.
- How to connect Stripe — the alternative processor, including Stripe Terminal at POS.
- How to set up receipt printing — add a thermal or PDF receipt after checkout.
Bring your whole store in-house
Take payments anywhere, keep one clean inventory, and never sell the same item twice. ResaleOS ties your phone checkout to eBay, Etsy, your storefront, and more.