Payment API for Developers

Payment API for Developers
Square’s powerful Payment API makes it easy for developers to accept mobile payments online and in-app.
by Square Jul 28, 2016 — 4 min read
Payment API for Developers

Square’s payment APIs offer a simple, elegant solution for developers who want to integrate fully functional payment processing into their websites or POS apps. Our payment APIs are ideal for merchants who do business online as well as in person.

When you use our payment processing APIs, everything is integrated so it’s easier for the back office to take care of bookkeeping. Square has rock-solid security and our payment APIs facilitate PCI-DSS compliant payment processing.

What payment APIs does Square currently offer?

Square offers developers multiple ways to take payments with our APIs:

Take online payments

If you’re building a website that needs to accept payments for goods or services, we have APIs for your eCommerce needs.

Take in-person payments

Take payments in person, in a store, or on the go while using Square hardware.


Square also offers other APIs to help extend your existing systems and allow you to manage customer data, track inventory, and more. You can even integrate payment data directly into your legacy CRM (customer relationship management), OMS (order management system), ERP (enterprise resource planning), and other business solutions.

Square’s payments APIs offer:


Square’s payment APIs are free to integrate into your software. For online sales, the only cost is 2.9% + 30¢ per payment transaction. Sales made with Square’s POS app are charged at our standard fees: 2.6% + 10¢ per swipe, chip card dip, or NFC payment. Manually entered transactions are charged at 3.5% + 15¢. For all Square APIs, there are no monthly fees, long-term contracts, or commitments.

Square’s payment APIs are PCI-DSS compliant

When you use Square payment APIs you can worry less about PCI-DSS compliance because we’ve got you covered. Customers’ credit card information never touches your website or app, so you don’t need to deal with PCI checklists to meet the Payment Card Industry Data Security Standards Council’s strict security requirements. Using Square’s payment processing APIs, we transmit customers’ payment data safely and securely from the start of the transaction to the end. Because Square is PCI-DSS compliant, you can use our payment APIs with confidence.

Square payment processing APIs transmit customers’ payment data safely and securely from the start of the transaction to the end. Because Square is PCI-DSS compliant, you can use our payment APIs with confidence.



Which of Square’s payment APIs is right for me?

API Best for:
Square Payment Form You are selling products online and have an eCommerce store. You want to process and take payments on your website, and you want the form to look like it’s part of your website.
Square Checkout You are selling products online and want the quickest way to start taking payments. You’re okay with linking to a Square-hosted page rather than embedding the payment form directly into your website.
Point of Sale API You need to take credit cards for in-person payments. You have your own app or custom point of sale (POS) but want to use Square hardware and Square for payment processing.
Square Connect API You want to manage customer data, manage employee data, and/or track inventory. Or you want to tie your payment data with your existing business solutions.

What currency are sales processed in?

In the United States, all transactions in our online payment APIs and in-person payment APIs are processed in U.S. dollars. Our payment APIs are also available in Canada, where payments are processed in Canadian dollars.

If I process payments with one of Square APIs, when are funds transferred into my account?

Get your payments in your bank account via ACH wire transfer as soon as two business days. If you need access to your money immediately, select Instant Transfer to send your money to your account in about a minute. It even works on weekends so you always have access to your funds when you need them.

Will I still need a payment gateway API or traditional merchant account with Square APIs?

No. When you use Square’s payment processing APIs, you don’t need a payment gateway API or merchant account. All you need is a U.S. checking account (or Canadian account if you’re in Canada) and a Square account. You can sign up for a free Square account in a couple of minutes and get started fast.

Case study: How Growl Movement used Square APIs to sell more beer.

Growl Movement is Oregon’s first standalone growler fill station. The shop’s two locations offer an impressive selection of rotating craft beers, hard ciders, and kombuchas that customers can enjoy onsite or take home in reusable growlers.

Using Square APIs, Growl Movement created an app that syncs with Square Point of Sale to show which kegs are getting low, so staff doesn’t have to manually check each one. The app then automatically removes kegs from the menu when they’re almost out. As an inventory management tool, the app is a huge time-saver. It’s also a great marketing tool that helps build customer loyalty. Customers can mark specific brews as favorites and the app sends them a push notification as soon as those kegs are tapped, which keeps folks coming back into the store.

Square's Payment API being used to measure leftover beers in kegs

What are you creating with Square APIs? Let us know on Twitter (tag @SquareDev) and we could feature you on this blog.

Want to learn more about our tools for developers? Visit our Developer Blog.

The Bottom Line is brought to you by a global team of collaborators who believe that anyone should be able to participate and thrive in the economy.


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