Payment API: How to automate your workflows with Modulr

Modulr By Modulr on 28 October 2023   •   17 mins read
<span id="hs_cos_wrapper_name" class="hs_cos_wrapper hs_cos_wrapper_meta_field hs_cos_wrapper_type_text" style="" data-hs-cos-general-type="meta_field" data-hs-cos-type="text" >Payment API: How to automate your workflows with Modulr</span>

If you’ve been looking for a payment API for your company, you’re likely doing so because:

  • You want to offer multiple payment methods so you can improve your customer experience.

  • Processing online payments for you and your customers through bank file transfers or manual input is tedious and risk-prone, and can delay the release of services or products.

  • Working with your bank to process payments on their schedule slows you down as you can only make payments Monday through Friday, and during certain times of day. It can take days before banks confirm transactions and settlements for you.

  • You and your finance teams are spending way too much time reconciling payments with your bank or current provider. As your volumes increase, so do the people hours needed to manage them.

  • You can’t launch new products or scale your business like the C-suite envisions, because your current payment setup can’t keep up.

As an embedded payment provider, we see these pain points all too often. We sat down with our payment experts to show you how you can use our technology to overcome these issues and even discover new opportunities. With their insights, we cover:

Modulr enables companies to embed payments directly into their platform with its powerful payment API. Learn how we can help you turn the way you handle payments into an opportunity driver. Contact us now.

What to look for in a payment API

There are many factors to consider as you’re looking for a payment application programming interface (API). Here are a few functionalities to keep in mind and why they could make a difference in your payment solutions:

Real-time transaction capability

Many payment providers only process payments in batches, at set times (i.e. every two hours or at the end of day). That causes delays for your customers, finance team and the release of products or services.

Instead, look for a payment API provider that makes payments on receipt of a request. This instant submission means you benefit from real-time payment processing, which:

  • Lets you and your customers make immediate payouts

  • Enables a faster release of goods or services, which improves your customers’ overall purchase experience

  • Enables quicker and automatic reconciliation 

Immediate payment settlements are also good news for liquidity and cash flow, which accelerates growth.

Direct integration with payment schemes

If payment speed is your number one concern, then find a provider with a direct integration to local payment schemes.

Direct integration is important because it avoids having additional layers between your system and the payment scheme. These additional layers can add delays and costs for you and your customers and can subject your transactions to additional compliance and risk controls (which can further increase processing times). When this connectivity occurs via API (instead of manual file transfers), you can send and receive payments with as little friction as possible.

A robust compliance and security track record

A payment API provider handles transactions and payment information on your behalf. It should instil trust to keep you and your customers safe while protecting your brand. Look for a provider that has:

  • Full authorisations to offer payment services to you and your customers

  • Strict compliance procedures to keep you and your customers safe

  • Secure API access and data safekeeping policies

  • A service level agreement that keeps your payments running at speed

Customisation of your payment experience

Look for a provider that offers more than multiple payment methods and doesn’t only act as a payment processor. An API can be a payment gateway to many complementary features, such as:

With the right provider, you could access these services to customise your payments offering.

For example, if you’re a lendtech platform, you can choose to disburse loans via cards and payment accounts for a smoother customer experience, which also provides greater visibility of funds. You can even let late payers quickly catch up on their loan payments by allowing them to initiate their transactions through Open Banking.

Working with an API provider that offers more can open up additional business opportunities and help you customise your offering.

Top level integration, support and ease of use

You may want a provider that makes it easy for you to access and automate your workflows with their payment API. Look for a provider that:

  • Supports you from day one as you plan and integrate their API into your system

  • Provides you with clear developer docs and guides

  • Offers an API that your developers can work with without hassle

  • If they can do this, then you’ll have a far greater chance of reaching your business goals or even exceeding your targets.

Here at Modulr, we can help you reach your payment milestones and beyond. Let’s take a deeper look at how our payment API works and the possibilities it offers.  

How Modulr’s payment API works

We’re an embedded payments provider that helps companies in the UK and Europe innovate the way they make and receive payments. Our payment API is the backbone of all our services. Here’s how you can get started with embedded payments through our RESTful API.

1. Share your vision with us

The first step in your Modulr journey is to speak with one of our payment experts. As soon as you contact us, we’ll set up a call where we’ll learn about your payment needs and pain points, along with your ideas for the future.

2. Get a dedicated team of experts who help you create your ideal embedded payment experience

Once we’re ready to work together, we’ll assign a small team of experts to you. This team consists of people across all domains, including product, IT, compliance, and business. They’ll work with their counterparts in your company to ensure all angles of our payment API and features are covered.

This team not only helps you during the onboarding and integration process, but is also there after you launch to help ensure your success for years to come. Our squad will work with your experts to come up with an embedded payment proposal built with our API. You can access whichever features you need to turn the plan into a reality, including multiple popular payment methods, such as:

You can also tap into complementary yet powerful features such as accounts on demand and card issuing.

Since you can tap into all these features via our API, you can build payment flows based on events in your system or other milestones. Whatever payment goal you have in mind, your Modulr team will support you through implementation and help bring your vision to life.

3. Connect our system to yours via a single API integration

We want you and your developers to get familiar with our payment API as soon as possible. We give you API keys so you can start playing in our test environment immediately. (Want to play in our sandbox right now? Click here to get your key). 

You’ll implement your new payment solution in our sandbox to ensure it works as intended. When it’s time to go live, you only need to switch a couple of lines of code and you’re set.

In addition to sending payment details and instructions to us through the API, you’ll also receive notifications of payment events as they happen through our webhooks. These proactive messages let you automate key parts of your business, like reconciliation, interface updates, and more.

4. Add and remove features as you see fit

Our products are modular (hence our name) so you can build your embedded payment infrastructure exactly as you envision it.

If you see a feature you need, you can incorporate it into your platform all without having to learn a new code library or upending your stack. Whenever you need to add or remove a feature, simply contact your Customer Success Manager so we can ensure a smooth transition.

Why choose Modulr as your payment API provider?

As a payments innovator active since 2016, we know how to help many industries offer a better payment experience to their internal teams, partners, and end customers.

Why choose Modulr and our payment API? Here are a few good reasons.

Automatically collect, segregate and reconcile payments from one API

Modulr's Payment API enables businesses like yours to manage and automate payments all through one connection point. Our API lets you automatically handle all steps of the payment process lifecycle, including:

  • Initiating the transaction

  • Segregating and disbursing funds according to your business model

  • Receiving confirmation of fund settlement

  • Reconciliation

Our payment API embeds into your system so it improves instead of disrupting your existing user interface (UI) and customer experience (CX). For example, whenever your customer needs to make a payment, your system will automatically forward an API request. We process the payment information through whichever system you specify, whether it be a Bacs Direct Debit or a euro payment via SEPA.

You can set up webhooks to receive automatic notifications for specific payment events (i.e. when funds settle in your Modulr account). You also can connect our webhooks to any tool that accepts an API, including ERPs, bookkeeping systems or even a custom-built dashboard.

Whatever manual payment flows you want to turn into automated ones, you can build it with Modulr.

Create accounts on demand for greater control over payments

We’re an Electronic Money Institution (EMI) with authorisations from the FCA in the UK and de Nederlandsche Bank in the EU. With Modulr, you can create payment accounts on demand for you and your customers, all via our API. Our account-on-demand service enables you to generate an unlimited number of accounts, complete with an account number and sort code or an IBAN.

With our accounts on demand, you and your customers can:

  • Receive funds from external bank accounts

  • Segregate and hold funds for future activity

  • Make payments instantly between accounts

  • Disburse funds to single or multiple parties

  • Track funds at any moment

Let’s take a marketplace as an example. Instead of having to rely on credit or debit card payments to let buyers transact with sellers, the marketplace can issue each customer an account on demand. This account allows buyers to pre-fund their purchase activity and sellers to receive proceeds from sales. Whenever the two parties transact, the payment clears immediately.

The seller can then hold on to the funds for however long they like before transferring them out to their bank account. Both you and your sellers’ finance departments will always be up-to-date with automatic reconciliation as each pay-in and pay-out goes through a unique account linked to each customer’s account.

With accounts on demand, you can take greater control of your payment workflows and customise them to fit your business model.

Get direct connectivity to payment schemes for the fastest payments possible

We know how important instant payment feedback is to you and your customers. That’s why we have a direct connection to some of the fastest payment schemes in Europe, including the UK’s Faster Payments (available 24/7) and Bacs. With our direct connection, you have:

  • Individual transaction processing (instead of batch processing)

  • An always on ecosystem with 24/7 access to payment schemes

  • Real-time notifications of payments

Consider a marketplace where transaction volumes go up during the evenings and the weekend. Some payment service providers handle payments in batches and process only during weekdays from 9am to 5pm, causing transaction backlogs and service delays. If a customer makes a purchase on a Saturday, they may see their checkout confirmed on the platform. However, the seller won’t receive their funds until Monday (or later) of the following week. And the customer may not know when their product will arrive and may even think twice about doing more business there.

With Modulr, those concerns don’t exist since our payment infrastructure never closes. Sellers can receive payments instantly, so they can despatch their services or products straightaway to ensure a quicker and more reliable purchase experience for your end customers.

Issue cards through our API for better transaction tracking (and revenue-generating opportunities)

Our API lets you issue payment cards for you and your customers. You can create both virtual and physical cards that can be single or multi-use. To issue a card, it is only a matter of making an API request. Within an instant, we’ll create the card and return all the information needed, including the card number, CVV2 code, and any other parameters you specify.

Card issuing can bring you numerous benefits, including cost reduction, custom branding, and even an additional revenue stream.

Let’s say you run a lendtech platform to make borrowing money more efficient for consumers. With our API, you can create a virtual card for each borrower. Once you’ve approved the loan request, you’ll transfer the funds to the card. Your customer will get their funds instantly, without having to wait for a bank transfer to settle.

As a bonus, each time they make a payment, you could collect a share of the interchange fee as the issuer. You can either keep those funds for yourself or pass them back to the borrower – it’s entirely up to you.

Eliminate manual payment reconciliation using our webhook notifications

As your business grows, finance departments often struggle to keep up with higher reconciliation volumes. Our payment API and its webhooks put an end to manual reconciliation for your finance team, so you’ll always have the most up-to-date books available.

Whenever a payment event happens on your platform, our system will notify you immediately through the API. You can connect the notification to any bookkeeping or resource planning tool that accepts webhooks. In turn, transaction status will update automatically.

Use an API with built-in security and compliance and excellent uptime

When you become a Modulr customer, your payment solutions fall under our regulatory umbrella. As a result, you and your customers get the same security and rule adherence that our regulations require of us.

With Modulr, you have:

  • Funds that are held and secured by the Bank of England or JP Morgan

  • Multiple layers of security and encryption so that your data and API connection stay secure.

  • PCI compliance, so card data is always safe.

  • Protection from Distributed Denial-of-Service (DDoS) attacks that allows legitimate users to access your service easily

Most importantly, we run 24/7 with a 99.99% uptime to ensure greater reliability and fewer outages to your payment infrastructure.

Who is Modulr’s API best for?

Companies of nearly all types and sizes can use our embedded payment tools and API to provide a better payment experience, including:

  • B2B

  • B2C

  • B2B2C

  • SMEs

We help these companies serve both their customers directly and their partners with payment solutions that enable growth. Here are just a few industries where we can help the most.

Payroll and wage advance

We help payroll and wage advance companies add more value to their customers by enabling them to make payroll payments instead of just calculating them. Firms like BrightPayand Salary Finance use our payment API to access electronic money accounts and Faster Payments to help their customers and partners quickly calculate and pay salaries to workers.

With Modulr, their customers can pay wages with a couple of clicks. The payments go instantly over our API and into the payment system. They don’t have to worry about reconciliation since our webhooks notify them whenever the salary payments occur.

Financial services

Our embedded payment tools help both sides in financial services: the traditional financial institutions and the financial technology companies.

Traditional financial service providers use our payment API and other embedded payment solutions to quickly build new fintech products. For them, they know how important it is to react to consumer demands, but also recognise that building an internal solution isn’t always the most efficient. Our technology enables them to move fast while still working with a regulated and licensed provider.

As for innovative companies, we help growing fintechs to not only compete with the incumbents but to go beyond with features like accounts, cards, and faster payment options.

For example, lending platforms use our services to make both the disbursement and collection process much quicker and manageable. Through our API, lenders can immediately transfer funds to a borrower using our access to the payment rails. They can also create accounts (with an account number and sort code or an IBAN) for each borrower, so their loan repayments are more intuitive, efficient and transparent. Lenders receive confirmation of repayment immediately as soon as funds hit these accounts, avoiding painful reconciliation and bad user experiences.


Travel companies use our embedded payments products to stay on top of reconciliation while dealing with high volumes. For example, online travel agencies use our card issuing services to create single-use virtual cards for each travel provider and partner. These virtual cards give the travel agency three key features:

  • Instant reconciliation

  • Security

  • A revenue stream from interchange fees

In a highly competitive but often low-margin industry like travel, our embedded payment solutions play a key role in supporting the bottom line.


Marketplaces leverage our payments API to meet customer demands for a better experience while simultaneously increasing turnover. They do so thanks to our on-demand accounts and connections to some of the fastest payment schemes around. 

These features enable their customers to top-up, hold funds, transact between them, and make external payments instantly from their platform. Marketplaces also won’t have to worry about reconciliation as our API’s webhooks notify them whenever a payment event occurs.

Discover how our API can also help your accounts payable become error free. 

Growing companies who handle high-ticket or high-volume transactions

If you’re a growing business with increasing payment volumes, you need a payment API to keep your growth plans on track. With our API, you can continue to take on more customers and volumes without creating admin and reconciliation challenges or disrupting your user experience.

Ready to see how we can help you? Let’s start talking today.

How Modulr’s payment API helped a growing wage advance company help more workers

Wagestream is a pioneer in pay advance services for frontline workers in the UK who often have variable monthly earnings. The service calculates a worker’s earnings as they happen, then enables them to access those funds whenever they want. Wagestream wanted to scale its solution to reach more people and turned to Modulr for help.

Modulr’s experts got to work seeing how they could automate their processes to make scaling possible. The resulting proposal had Wagestream:

  • Incorporate account-on-demand capabilities for each partner employer to keep funds for future wage payments

  • Let each partner employer issue an account for their workers to receive earned wages into

  • Automate instant transfers between employer and worker whenever they wanted to access their wage

  • Enable instant payout through Faster Payments from the worker’s EMI account to a bank account of their choice

Wagestream immediately took to the proposal and began development. Thanks to Modulr’s API and documentation, they rolled out their new embedded payment solution quickly and with ease. The results speak for themselves: today, over one million frontline workers use Wagestream to make work and money more inclusive, fair and rewarding, all with Modulr’s payment technology.

Read more about Wagestream’s success story here.

Automate your payment flows with Modulr’s API

Now you know how Modulr can help you use a payment API to automate processes, speed up payments, open new revenue streams and build the experiences your customers deserve.

Contact us today to find out how we can change the way you process payments.