Create an Account and Application
To start building on the Square Developer Platform, create a free Square developer account and register an application. Square takes you through sign-up tasks on a short series of pages. You're asked for information that Square needs to open your Square account and create your first application. Be ready to provide the following:
Information about you. Your name, an email address, a new password, and your country.
Business name. If you're employed by a Square merchant, enter the merchant's name. Otherwise, you can enter the name of your own software development business.
Application name. This is the name of your project and does not need to match the branding that your released application will have.
Use case. This is optional. You can skip this page if you're not sure what business scenario your application will address.
Language used. This is optional. You can skip this page.
Audience. This is optional. You can skip this page.
The optional information is used to help Square improve your experience with the developer tools by giving you samples, help content, and language snippets based on your choices. You can provide this information later on the App details page in the Developer Dashboard.
Open the Square Developer sign-up page. If you already have a Square account, sign in and go to Make your First API Call.
Provide information for your account and application.
When the sign-up process is complete, Square opens your new application in the Developer Dashboard. You're now ready to explore Square APIs using the Square Sandbox
If you're signed in with a pre-existing Square account, you can access the Developer Dashboard using the Account menu:
When you're ready to take payments in the production environment, you must activate your Square account at squareup.com/activation.
If you need more assistance, contact Developer Support or ask for help in the Developer Forums.