How ISVs Can Benefit from Integrated Payments
Published - 21 January 2025
Revised - 08 September 2026
Libby James is the founder and Managing Director of Merchant Advice Service. Since 2016, she has worked directly with businesses and payment providers across merchant accounts, card processing, payment gateways and complex provider requirements.
Libby specialises in high-risk, declined and harder-to-place merchants, as well as businesses requiring specialist payment methods, integrations or international support. She writes and reviews Merchant Advice Service content, drawing on practical experience gained from real merchant enquiries and provider relationships.
For an Independent Software Vendor — ISV — payments can be much more than another integration.
Once customers already use your software to run an important part of their business, payment processing can become part of the product itself.
That can potentially allow an ISV to:
But there are several ways to do it.
An ISV might simply integrate with a payment gateway.
It might negotiate a commercial revenue-share agreement.
It might offer a more deeply embedded or white-label payment proposition.
Or, at the more complex end of the market, it might explore a Payment Facilitator or managed PayFac model.
The important decision is not simply whether to integrate payments. It is how much of the payment experience, merchant relationship, economics and operational responsibility the software business actually wants to own.
This guide is primarily for established ISVs, vertical SaaS companies and software platforms with an existing portfolio of business customers that accept payments.
Typical examples include software serving:
If you are a merchant looking to connect payments with the software you already use — such as EPOS, ERP, CRM, booking or accounting software — read our Integrated Payments Solutions UK guide.
If you are a software company or platform exploring how payments can become part of your own proposition, including payment monetisation and broader platform-payment models, read our Embedded Payments for SaaS and Platforms guide.
For wider strategic guidance on payment architecture, provider selection and payment infrastructure, explore the Merchant Advice Service Payments Strategy Library.
For an ISV, integrated payments usually means connecting payment functionality directly into the software used by the ISV's customers.
Instead of the customer operating:
software → separate terminal/gateway → separate reporting → manual reconciliation
the experience can become:
software → payment request → payment provider → payment result → software workflow.
Depending on the product, that payment could relate to:
For an ISV, the real value of integrated payments is not that the software can take a card payment. It is that the payment becomes part of the workflow the customer already depends on.
The terms overlap, but it is useful to separate them.
| Integrated Payments | Embedded Payments |
|---|---|
| Payment functionality connects with the software | Payments become part of the software company's broader product proposition |
| Can be primarily a technical integration | Often includes commercial and merchant-lifecycle considerations |
| Payment provider may remain highly visible | Platform may control more of the customer experience |
| Revenue share may or may not exist | Payment monetisation is often an important objective |
| Merchant may contract directly with provider | Contract and merchant structure depend on the embedded model |
| Lower operational ownership may be possible | Platform may take greater responsibility for onboarding, support or payment operations |
A software company can therefore have a very good integrated-payment product without necessarily operating a deeply embedded payment model.
For the wider platform models, see our Embedded Payments guide.
There is no single structure every software company needs to follow.
The ISV refers customers to a payment provider.
The customer establishes its payment relationship with the provider, while the software supplies the technical integration.
The ISV may receive a commercial referral payment depending on the agreement.
This can be relatively simple operationally because the payment provider retains most responsibility for:
The ISV develops a deeper strategic relationship with one or more payment providers.
This may include:
Payments become a more substantial part of the software proposition.
The platform may control more of:
With a white-label model, more of the payment experience can appear under the software company's own brand.
Exactly what can be white-labelled — and which organisation retains responsibility for underwriting, contracts, settlement and regulated activities — depends on the provider and model.
Read our White-Label Merchant Processing guide.
At the deeper end of the market, software companies may explore a Payment Facilitator structure or models commonly described as managed PayFac or PayFac-as-a-Service.
These can provide significantly more control over merchant onboarding and the payment proposition, but they also introduce additional operational, risk, acquiring and potentially regulatory considerations.
Read our Payment Facilitators: How the Model Works for Merchants and Platforms guide.
This is one of the most useful strategic questions an ISV can ask.
| Area | Lower-Ownership Model | Higher-Ownership Model |
|---|---|---|
| Merchant onboarding | Provider-hosted | Embedded or platform-controlled journey |
| Pricing | Provider sets merchant pricing | Platform may have more commercial control |
| Brand | Provider visible | Co-branded or white-labelled |
| Merchant support | Provider-led | Platform may become first line |
| Underwriting | Provider-led | Platform may contribute data/processes within the agreed structure |
| Risk monitoring | Provider-led | Greater platform involvement may apply |
| Payment revenue | Referral/revenue share where agreed | Potentially deeper participation in payment economics |
| Technical ownership | Pre-built integration | Custom APIs and payment infrastructure |
Greater control can create greater commercial opportunity.
It can also create greater:
ISVs should not take ownership of parts of the payment stack simply because a provider makes it possible. They should own the parts that create strategic value for the software business.
Payment partnerships can potentially create recurring revenue for software companies.
The exact commercial model varies considerably.
Possible structures can include:
The ISV should understand exactly:
Consider a software platform that generates payment revenue but forces its customers onto commercially uncompetitive processing.
That may increase short-term payment income while making the software proposition weaker.
A sustainable model needs to work for:
the ISV + the payment partner + the merchant.
The merchant still needs appropriate:
For a detailed explanation of the payment-cost stack, read our Payment Gateway Fees UK 2026 guide.
Recurring payment-related revenue can make payments an important part of a software company's commercial model.
However, it would be misleading to say that integrating payments automatically increases the valuation of an ISV.
Business valuation can depend on many factors including:
Payment revenue should therefore be assessed as part of the wider SaaS economics rather than treated as an automatic valuation multiple.
Before approaching payment partners, an ISV should understand the payment opportunity across its existing portfolio.
Useful information includes:
An ISV has:
1,000 active customers.
If 600 of those customers process an average:
£40,000 per month
through the software, the potential portfolio payment volume is:
£24 million per month
or:
£288 million per year.
This is an illustrative MAS calculation only.
But it demonstrates why an ISV should evaluate payment-provider negotiations at portfolio level, not simply as one software integration.
An ISV integrating payments is not bringing one merchant to a payment provider. It may be bringing an entire merchant distribution channel.
A provider can have excellent developer documentation and still be the wrong payment partner.
Imagine an ISV serving:
If the proposed provider has limited appetite for those merchants, a technically excellent integration may have low customer adoption.
Before integrating, establish:
Integrated merchant onboarding can be just as important as integrated payment acceptance.
The customer journey might be:
software account → payments application → KYB/KYC → underwriting → merchant activation → payments enabled.
An ISV should understand:
There are clear benefits to having a primary payment partner.
These can include:
But there are also risks.
A single provider may not support:
The ISV also becomes more dependent on one payment infrastructure provider.
For larger platforms, possibly.
A multi-provider strategy can potentially support:
But every additional integration creates more:
Platforms considering multiple PSPs or acquirers should also read our Payment Orchestration UK guide.
We would divide provider selection into eight areas.
For the wider technical design questions, read our Payment API Integration guide.
The answer should be driven by the customers the software already serves.
Potential requirements include:
Yes — that is usually where the value of the integration appears.
Consider a booking-software company.
A weak payment integration might simply add:
Pay Now.
A deeper integration could potentially support:
booking created → deposit calculated → payment collected → booking confirmed → token stored → balance scheduled → payment reconciled.
Or for an ERP:
invoice created → payment request sent → customer pays → accounts receivable updated → settlement reconciled.
The software company should therefore design around the customer's workflow rather than merely inserting a checkout component.
Payments create several different events:
The software should decide which of those events matter to its customers and how they map into the underlying business records.
For example:
customer → order → payment → settlement.
Strong transaction identifiers and reporting can make reconciliation significantly easier.
Read our Payment Reconciliation guide.
ISVs should design for failure as well as success.
Possible scenarios include:
The software needs clear rules for:
An ISV payment integration is only as good as the workflow it provides when the payment does not behave exactly as expected.
This should be agreed commercially before the payment product launches.
Possible models include:
The merchant contacts the payment provider directly.
The merchant contacts the software company, which escalates payment issues where required.
Responsibilities are split according to the type of issue.
For example:
| Problem | Possible Owner |
|---|---|
| Software workflow | ISV |
| API integration | ISV + payment provider |
| Merchant underwriting | Payment provider |
| Settlement | Payment provider/acquirer |
| Terminal hardware | Provider/terminal supplier |
| Customer software account | ISV |
The exact structure varies, but the merchant should not be left to discover ownership during an incident.
White labelling may be attractive where the software company wants greater control over:
But the term white label can describe very different models.
Ask:
Read our White-Label Merchant Processing guide.
No.
A software company does not need to become a traditional PayFac simply because it wants to offer integrated or embedded payments.
Alternatives can include:
The more useful question is:
What payment responsibilities does the ISV actually want to control?
For a full explanation of the operating model, see our Payment Facilitator guide.
An ISV integrating with another payment provider does not automatically become a regulated payment institution.
However, the regulatory analysis can change depending on what the platform actually does.
The FCA states that firms providing payment services as a regular occupation or business activity in the UK generally need the appropriate authorisation or registration unless an exclusion or exemption applies.
The FCA also specifically warns that marketplaces, booking businesses and other businesses bringing buyers and sellers together may potentially be providing payment services where they receive customer money before passing it to another party.
An ISV should therefore obtain specialist regulatory advice where the proposed model involves the platform itself:
FCA — Payment Services Regulations and Electronic Money Regulations
FCA — Consider Whether You Provide Payment Services
Technical integration and regulated payment provision are different questions. The closer a software platform moves towards controlling the movement of money, the more important the regulatory structure becomes.
PCI responsibilities depend on the technical architecture and the role the software company performs.
An ISV should establish:
PCI SSC also maintains its Secure Software Standard specifically for software vendors and developers producing software that supports or facilitates payment transactions.
PCI SSC — Secure Software Standard
PCI requirements should be confirmed with the relevant payment provider, acquirer, QSA or appropriately qualified PCI professional.
The test plan should extend well beyond:
“Can we make a payment?”
Depending on the product, test:
A full portfolio launch is not always the best first step.
A controlled pilot can help establish:
One useful sequence is:
partner selection → integration → internal testing → pilot merchants → measure → refine → broader rollout.
This needs to be considered before signing the first payment partnership.
Ask:
For businesses dealing with stored credentials, see our Changing Payment Gateway: Stored Cards, Tokens & Recurring Payments guide.
A payment partnership can become deeply embedded in a software company's product. Exit architecture should therefore be considered at the same time as integration architecture.
For some larger platforms, separating internal business logic from provider-specific payment logic can make future development easier.
For example, the platform's internal system may maintain its own references for:
Those internal references can then be mapped to provider-specific objects.
This can potentially make it easier to:
Whether that additional architecture is justified depends on the size and technical strategy of the platform.
Merchant Advice Service would evaluate an ISV payment opportunity across seven areas.
Who are the merchants, how much do they process and what sectors do they operate in?
Where does payment functionality genuinely improve the software workflow?
Can the payment partner accept and support the ISV's actual merchant portfolio?
How will merchant pricing and ISV payment revenue work?
Who owns onboarding, underwriting, support, settlement, risk and merchant relationships?
How are payments integrated, secured, reconciled and supported?
Can the software business evolve or change payment partners without rebuilding the entire product?
Portfolio → Product → Provider Fit → Commercial → Ownership → Architecture → Portability.
The best payment partnership is not the one that generates the highest theoretical revenue per transaction. It is the one that creates a sustainable payment product for the ISV and its merchants.
Merchant Advice Service helps ISVs, SaaS companies and software platforms understand payment-provider and partnership options.
A review can consider:
MAS does not act as an acquiring bank, processor or regulatory adviser.
Our role is to help software businesses understand the payment model they require and identify providers or specialist payment partners that may fit that model.
For broader payment models, read our Embedded Payments guide, White-Label Merchant Processing guide and Payment Facilitator guide.
For wider strategic guidance, explore the Payments Strategy Library or The Payments Directory®.
The FCA explains the scope of regulated payment services in the UK and the circumstances in which businesses providing payment services may require authorisation or registration.
FCA — Payment Services Regulations 2017 & Electronic Money Regulations
The FCA specifically advises marketplaces, booking businesses and other businesses bringing buyers and sellers together to consider whether their activities may amount to providing payment services, particularly where they receive customer funds before passing them to another party.
FCA — Consider If You Provide Payment Services
PCI SSC's Secure Software Standard provides security requirements for software vendors and developers whose software supports or facilitates payment transactions.
PCI SSC — Secure Software Standard
PCI DSS v4.0.1 is the current PCI Data Security Standard and defines security requirements for environments involving payment account data.
Merchant Advice Service is an independent payments information, comparison and provider-matching service.
MAS may receive commission, referral fees or other commercial remuneration from some payment providers or partners where a business chooses to proceed following an introduction. This does not determine the factual information, payment-model analysis or provider-selection principles included in this guide.
Integrated-payment, embedded-payment, white-label and PayFac models vary significantly between providers. The terminology used by individual payment companies should not be assumed to describe identical legal, commercial or acquiring structures.
Payment-related revenue is not guaranteed and depends on the commercial agreement between the ISV and payment partner, merchant adoption, payment volumes and other contractual factors.
Integrating payment technology does not automatically make an ISV a regulated payment-service provider. However, platforms undertaking activities that fall within the UK payments regulatory perimeter may require FCA authorisation, registration or another appropriate regulatory structure. Businesses should obtain specialist regulatory advice where required.
PCI DSS and payment-software security requirements depend on the ISV's technical architecture, access to payment account data and role within the payment environment. Formal PCI guidance should be obtained from the relevant acquirer, payment provider, QSA or appropriately qualified professional where necessary.
Merchant acceptance remains subject to payment-provider and acquiring-partner underwriting and risk appetite.
Payment-provider functionality, APIs, commercial terms, regulatory requirements and technical integrations can change.
Merchant Advice Service does not guarantee merchant approval, payment revenue, technical compatibility, implementation timescales, regulatory status or commercial outcomes.
Payments, PCI and regulatory information last checked: 28 August 2026
This guide provides general payments information and should not be treated as legal, regulatory, accounting, investment, valuation, cybersecurity or formal PCI compliance advice.
Written or reviewed by Libby James, founder of Merchant Advice Service and specialist in merchant payments and complex provider requirements.