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How to Automate Payments Using API: A Quick Guide for UK Businesses

Saim Jalees

11.05.26 (last updated)

Read time 7 minutes

Managing invoices, payroll, marketplace payouts, and international transfers across multiple systems can create time-consuming manual work and increase the risk of operational errors. Could connecting your payment workflows through API integrations help improve efficiency and reduce complexity?

In this guide, we've explained how payment API integrations work, how businesses can use them to automate repetitive payment processes, and what to consider when choosing a provider for your operational needs.

We've also explained how Wise Business can support payment automation with flexible API integrations and global payment capabilities.

*Disclaimer: The UK Wise Business pricing structure is changing with effect from 26/11/2025 date. Receiving money, direct debits and getting paid features are not available with the Essential Plan which you can open for free. Pay a one-time set up fee of £50 to unlock Advanced features including account details to receive payments in 22+ currencies or 8+ currencies for non-swift payments. You’ll also get access to our invoice generating tool, payment links, QR codes and the ability to set up direct debits all within one account. Please check our website for the latest pricing information.

Availability of features, currencies, and payment methods varies by region.

Key takeaways

Topic	Summary
Payment APIs	Let your systems trigger payments and exchange data automatically
Integration process	Typically involves setup, credentials, build, testing, and monitoring
Automation benefits	Can help reduce manual work, minimise operational errors, and improve efficiency
Provider choice	Depends on use case, such as international payments or marketplaces
Risk considerations	Test thoroughly, monitor live payments, and review provider documentation

Discover Wise Business 🔍

What does API stand for?

API stands for Application Programming Interface. It lets one software application communicate with another in a standardised way.¹

What is a payment API?

A payment API is an application programming interface that acts as a software intermediary, enabling communication between applications for processing financial transactions. Your systems can trigger payments, retrieve transaction data, create recipients, and receive status updates, all without relying on manual steps.²

How does API integration work for payments?

A typical payment API workflow looks like this:

Your app, website, ERP, or accounting platform sends a request to the provider’s API.
The provider authenticates the request using credentials such as an API token or OAuth access token.
The provider processes the instruction, such as creating a payout or returning account data.
Your system receives a response and can also listen for follow-up events through webhooks or status updates.³

For UK businesses, this can currently support automation of supplier payments, payroll runs, invoice settlement, or platform payouts without moving data manually between tools.⁴

What can payment APIs automate?

Recurring supplier payments

Payment APIs can automate recurring supplier payments by triggering transfers based on predefined schedules or contract terms. Your system sends funds when an invoice is due or a billing cycle is reached, without requiring manual initiation.

This can help reduce missed payments and late fees while standardising workflows for businesses with regular vendor relationships.

💡 Wise API lets you automate recurring transfers and standing orders directly from your systems, helping support timely supplier payments without manual input.

Payroll and contractor payouts

APIs can automate payroll by integrating directly with HR or payroll systems, triggering payments once salary calculations are finalised. Employees and contractors can be paid accurately and on time without manual file uploads or bank processing.

For businesses managing international teams, APIs can support multi-recipient payouts in different currencies, helping simplify global payroll operations.

💡 Wise API supports automated payroll and mass payouts across multiple recipients and currencies, making it easier to pay global teams from one platform.

Invoice-triggered disbursements

Payment APIs can connect with invoicing or accounting systems to trigger payments when invoices are approved. Once a status changes (e.g. “approved” or “due”), the API initiates the transfer without manual input.

This can help reduce delays between approval and payment and streamline procure-to-pay workflows.

💡 Wise API can generate payments directly from invoicing software, helping automate invoice payments and reduce manual processing between systems.

Marketplace seller payouts

For platforms and marketplaces, APIs enable automated payouts to sellers based on predefined rules such as order completion, refund windows, or commission splits. Funds distribute programmatically to multiple recipients at scale.

This can help remove manual payout handling and support scalable operations as transaction volumes grow.

💡 With Wise API, you can embed payouts directly into your platform and send money to users globally, including recipients without a Wise account.

Reconciliation and status tracking

APIs provide real-time access to transaction data, allowing systems to automatically reconcile payments against invoices, orders, or internal records. Status updates and webhooks notify your system when payments are complete, fail, or remain pending.

This can improve visibility and reduce manual tracking across systems.

💡 Wise API provides real-time payment updates and integrates with your tools, helping automate reconciliation and improve visibility over payment flows.

Multi-currency payment operations

Payment APIs automate currency conversions and international transfers by integrating FX handling directly into your workflows. Businesses can currently send, receive, and manage payments across currencies without switching between platforms.

This can be particularly useful for businesses operating across borders or managing multiple currency balances.

💡 Wise API enables automated international payments and multi-currency workflows, helping you manage global transactions directly within your systems.

How to integrate a payment API

Most payment API projects follow a similar path:

1. Choose the right provider

Start with your actual use case. If you need international payments, review payout coverage, FX support, and developer tooling. For platforms or marketplaces, prioritise onboarding, connected accounts, and payout controls.⁵

2. Create a business account

Most providers currently require a business account before you can use live credentials or advanced payout capabilities. Providers also currently offer developer documentation to help teams get started.⁶

3. Generate credentials and access the sandbox

Start by creating API credentials and testing in a sandbox or developer environment. Providers like PayPal currently offer REST API guidance and payout integration docs.⁷

4. Build the integration

Integrate through direct API calls, SDKs, plugins, or embedded components depending on the provider and your setup. Stripe Connect, for example, is currently designed for platforms and marketplaces that need to orchestrate money movement across multiple parties.⁸

5. Test payment flows and edge cases

Before launch, test your integration in the sandbox environment to verify authentication, payouts, webhooks, and reconciliation flows all behave as expected, including how your system handles failures and edge cases.⁹

6. Go live and monitor

Once live, monitor payment statuses, failures, and operational exceptions. Most providers currently expose status data or event notifications so you can build internal monitoring.¹⁰

How to choose the right payment API

When comparing providers, focus on what matters most to your workflow:

supported countries and currencies
batch payout capability
sandbox and documentation quality
authentication method
webhook or event support
payout controls and reconciliation features
pricing transparency

For many UK businesses, the most suitable option is the provider that aligns with their specific payment flows, systems, and operational needs. Choosing a solution that aligns with your existing infrastructure can help reduce integration time and operational complexity linked to provider-specific logic.¹¹

Automate global payment workflows with Wise Business

Managing automated payment workflows across borders can introduce operational complexity, especially when dealing with multiple currencies and systems.

This is where the Wise API can help. All you have to do is:

Open a Wise Business account and create a Sandbox environment for testing.
Generate API tokens to securely connect your systems with Wise.
Use the API documentation to build payment, payout, payroll, or reconciliation workflows into your tools.
Test payment flows in the Sandbox before going live.
Launch live API keys and automate international payments, batch payouts, and multi-currency operations directly from your systems.

With Wise Business, you can:

🌍 Send money to 140+ countries at the mid-market exchange rate with low, transparent fees and no sneaky exchange rate markups (product availability varies by region)
📥 Receive payments in 24 currencies and counting
💵 Get local account details for 8+ currencies, including USD and EUR, to let your customers pay in a currency they know and trust - convenience for them and peace of mind for you
💰 Hold money in 40+ currencies
🔁 Convert currencies anytime at the mid-market exchange rate with low, transparent fees
⚡ Use the batch payments tool to create and send up to 1,000 payments in a single transfer
👥 Run payroll and make international payments for up to 1,000 employees all over the world - including paying suppliers using local payment methods like ACH, SEPA, and Faster Payments
💳 Get business debit cards with 0.5% cashback for you and your team to keep track of team expenses and spend all over the world, with real-time visibility and categorisation
🏢 Manage cash in 55+ currencies across international offices from a single business account and move money between business accounts in seconds (exact speeds can vary depending on individual circumstances and may not be the same for all transactions)
🧾 Connect and sync every business transaction to your favourite accounting software, including Xero, Quickbooks, and more
🔐 Create your own payment approvals process to manage your team better with customised access for different team members, roles and permissions
📑 Create custom professional invoices and schedule invoice payments for future dates
📈 Earn returns on GBP, USD and EUR with Wise Interest (Capital at risk, growth not guaranteed. Your money is at risk if governments default or interest rates go negative. Visit https://wise.com/gb/interest/ to find out more)
🔗 Create payment links and QR codes to get paid easily
⚙️ Automate payouts with the Wise API (comes with 24/7 customer support, a sandbox account to test integrations, API tokens, and clear documents on how to implement and make the most of our API)

Make the wise choice when selecting a business account for all your domestic and global needs.

Be Smart, Get Wise.

FAQ

What is an API token or API key?

An API token or key is a credential that authenticates requests made by your application. Providers like Wise API let you generate credentials directly.

What is a sandbox environment?

A sandbox is a test environment that mirrors real-world transactions. Many providers currently offer sandbox access for testing integrations before going live.¹²

What are batch payments?

Batch or mass payouts let businesses send multiple payments in one workflow. PayPal’s Payouts API currently supports sending up to 15,000 payments per API call.¹³

What are the 4 main types of API?

If you’re researching payment API integrations more broadly, here are the main categories:

Public APIs: available for external developers
Partner APIs: shared with selected third parties
Internal APIs: used inside a single organisation
Composite APIs: combine multiple requests or services in one integration layer^1,14

Sources:

Sources last checked on 11 May 2026

*Please see terms of use and product availability for your region or visit Wise fees and pricing for the most up to date pricing and fee information.

This publication is provided for general information purposes and does not constitute legal, tax or other professional advice from Wise Payments Limited or its subsidiaries and its affiliates, and it is not intended as a substitute for obtaining advice from a financial advisor or any other professional.

We make no representations, warranties or guarantees, whether expressed or implied, that the content in the publication is accurate, complete or up to date.