FAQ

How do I retrieve an affiliate key?

You need to create your key by logging in to the Developer page of the SumUp Dashboard. Details on its implementation can be found in our step-by-step guide.

How do I set up OAuth credentials?

You can create credentials by logging in on the SumUp Developer page and navigating to the “Create Client Credentials” section. Detailed information on how to authenticate further can be found in our step-by-step guide or in this video.

How do I check completed transactions?

Our API provides endpoints where you can query transaction statuses, either for a single transaction or a list of transactions based on search criteria.

Can I integrate SumUp to my website?

Yes, as a SumUp merchant you have the option to integrate SumUp’s eCommerce service with a webshop plugin or via direct integration.

SumUp’s official plugin supports integrations with WordPress/WooCommerce.

For PrestaShop users we recommend this plugin developed by a SumUp partner.

For WIX users we recommend following their native solution.

The direct integration option uses the SumUp eCommerce Checkout API, intended for developer utilisation. All information can be found in our Online Payments section. Before following our guides, make sure to request a sandbox merchant account.

Note

For all webshop plugins and direct integration, make sure your merchant account is fully on-boarded before purchasing the plugin or starting the integration. Please share your client_id to activate the “Payments” scope through our contact form.

Can I get a sandbox merchant account?

To get started with SumUp, first log in. If you don’t have a SumUp user account yet, register first. Then follow the Activate my account steps.

Once your user account is active, go to https://developer.sumup.com/, open the sandbox merchant account setup page by clicking Create sandbox merchant account in the right-side navigation, and select Set up sandbox merchant account. Your sandbox merchant account is created for the same country as your live merchant account.

Once your sandbox merchant account is created, copy and store the generated username (format: 32characters@developers.sumup.com) and unique password securely.

Note: You won’t be able to access the password again, so store it safely before dismissing the message.

Which operating systems are supported by SumUp card readers?

The SumUp card readers support iOS & Android.

I need help with a technical question.

Sure. You can reach us through our contact form.

Which currencies are supported by SumUp?

We provide support coverage on three continents and in the following currencies:

• EUR
• GBP
• USD
• BRL
• CLP
• PLN
• CHF
• SEK
• CZK
• NOK
• DKK
• HUF
• BGN

Which libraries are supported by SumUp?

SumUp maintains multiple SDKs and APIs to simplify your integration work across online and in-person payments.

Online payments SDKs

• Node.js / TypeScript, Go, Python, Java, PHP, .NET, and Rust SDK guides cover server-to-SumUp API calls for card-not-present flows.
• Use these when you’re building checkout pages, recurring billing, or want to control the full online payments lifecycle via API.

Card-present SDKs

• Android SDK and iOS SDK let you embed our reader experience inside native apps.
• Android API and iOS URL scheme are lightweight options for launching the SumUp app to take a payment.
• See the terminal payments docs for installation and certification requirements.

Server SDKs

• All server-side SDKs (Node.js, Go, Python, Java, PHP, .NET, Rust) support both online payments and remote reader management via the same client libraries.
• They handle authentication, pagination, and typed payloads so you can call any SumUp REST endpoint from your backend.

Cloud API for Solo readers

• The Cloud API triggers card-present transactions on Solo readers from any backend or platform that can make HTTPS calls.
• Use it when your POS runs on web, desktop, or another environment that can’t embed the native Android/iOS SDKs but still needs in-person payments.

I'm receiving a "403" error with a "request_not_allowed" error message. What does this mean?

This error message indicates that the “payments” scope is not enabled for your application. Contact us through our contact form for activation assistance.

Do SumUp card readers work in a standalone setup?

Our devices are designed to follow a payment flow that doesn’t allow them to operate unattended.

Can my web app communicate with SumUp devices?

Yes. For web applications running on mobile devices where the SumUp app is installed, you can call the SumUp app via URL. Read more on this preferred merchant approach in our API Payment Switch guide.

What is a sandbox merchant account?

SumUp sandbox merchant accounts mirror regular merchant accounts and follow the same rules. However, sandbox merchant accounts don’t connect to service providers and don’t process transactions with real funds.

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