Works with Square
Free stamp card for Square sellers
On Square’s free plan? Add a stamp card for $0. Connect Square once to KANJIN (kanjin.app), and every visit stamps itself when a customer on your card pays.
- Connect Square free
- No app for customers
- Unlimited customers
- No credit card
Three steps
How it works at your counter
01
Connect Square in Settings
One button. KANJIN reads payments and customers, and nothing else: it never charges, refunds or changes anything in Square. Disconnect from the same button whenever you like.
02
Customers join with their phone number
At the counter, or by scanning the poster you print. There is no app to download and no card to carry. Their number is the card.
03
They pay with Square, and the stamp happens
Switch on “Give a stamp when a customer on the card pays with Square”. A customer already on your card gets their stamp for that visit. Nobody types a number.
Side by side
Square Loyalty and KANJIN
If you are on Square’s free plan, this is what the two cost you.
| What it costs you | Square Loyalty | KANJIN |
|---|---|---|
| Price | Square Plus $49 per location a month | $0, with no time limit |
| Works with your Square register | Built into Square | Connects to Square free, and reads payments only |
| Free plan | No. 30-day loyalty trial | Yes, with no time limit and no card |
| Download your whole customer list | Not stated | Free, from Settings, any time |
| Google review requests | Not stated | 20 a month free |
| Daily ledger and shift notes | Not stated | Free, in the same app |
Square facts read on Square’s own US pages on 10 Oct 2026: Square press release on Square Plus, Square Loyalty page. US prices. We make KANJIN, so read with that in mind. The longer comparison. Square is a trademark of Block, Inc. KANJIN is not affiliated with Block, Inc.
In the same account
What else you get, free
The stamp card is not the whole of it. Everything here is on the free plan.
Questions
Questions Square sellers ask
- Do I have to leave Square?
- No. KANJIN sits next to it. You keep taking payments exactly as you do now, and Square stays the register.
- What happens to customers who are not on the card yet?
- They join at the counter, or by scanning your poster with their own phone. After that, their Square payments stamp them. A payment never adds anybody by itself: joining stays the customer’s choice.
- Does KANJIN see my Square money?
- It reads payments, to know who paid and when, and customers, to match a payment to someone on your card. It never charges, refunds or changes anything in Square.
- What if I disconnect?
- One button in Settings, or from Square’s side. KANJIN deletes the stored connection and stops reading. Your customers and their stamps stay exactly as they are.
Start at your counter today—for free.
No credit card, no time limit, and no app for your customers to download.
- Calculators need no account
- The back office is free
- Cancel any time