Integrated Card Machines & EPOS Compatibility: What to Check Before Choosing or Switching Provider

An integrated card machine should do more than accept a payment.

For many established businesses, the terminal forms part of a much wider payment system connecting:

• the till or EPOS system;
• the card terminal;
• the payment gateway or terminal software;
• the acquiring bank or payment provider;
• refunds;
• settlement;
• reporting; and
• finance and reconciliation systems.

That means changing card-machine provider is not always as simple as replacing one terminal with another.

A new provider may offer better transaction pricing or newer hardware but fail to integrate with the EPOS platform the business already uses.

Alternatively, a business may discover that its existing EPOS integration is effectively restricting which acquiring providers it can consider.

The right question is therefore not simply “Will this card machine take payments?” It is “Will this payment setup work with the rest of our business?”

This guide explains what UK businesses should check when choosing an integrated card machine, changing payment provider or reviewing an existing EPOS/payment integration.

Quick Summary

• An integrated card machine communicates with an EPOS, till or other business system rather than operating entirely independently.
• Integration can remove the need for staff to manually enter the transaction amount into the terminal.
• Not every payment provider integrates with every EPOS platform.
• A card terminal being technically compatible does not necessarily mean the acquiring provider is compatible with the EPOS integration.
• Some EPOS systems restrict the payment providers or terminal integrations they support.
• Businesses should confirm compatibility before signing a new merchant-services or terminal contract.
• Switching provider may require new terminals, configuration, software changes or integration work.
• Multi-site businesses should consider central reporting and rollout as well as individual terminal compatibility.
• Changing the payment architecture can also affect PCI DSS scope and validation requirements.
• Historic refunds and reporting may require access to the old provider after the new terminals go live.
• A lower transaction rate is not necessarily a saving if the new solution creates integration or operational costs.

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What Is an Integrated Card Machine?

An integrated card machine communicates directly with another system used by the business, most commonly an EPOS or till system.

Instead of a member of staff entering:

£47.85 into the till

and then manually typing:

£47.85 into the terminal,

the payment amount can be passed electronically from the EPOS system to the card machine.

Once the payment has been processed, the payment result can then be returned to the EPOS system.

This can create a much more joined-up transaction flow.

EPOS-connected terminals are one form of integrated payment, but larger businesses may also need payments to connect with ERP, CRM, accounting, booking or other operational systems.

Our Integrated Payments Solutions UK guide explains how the wider payment environment can connect across business software and workflows.

Integrated vs Standalone Card Machines

Neither model is automatically better.

A small independent retailer may be perfectly happy with a standalone terminal.

A restaurant group, hotel, multi-site retailer or high-volume venue may gain considerably more operational value from integrated payments.

MAS View

The more transactions, staff, locations and systems a business has, the more important payment integration usually becomes.

What Does EPOS Integration Actually Do?

The exact functionality depends on the systems involved, but an integrated payment journey can potentially allow:

• transaction values to pass automatically from EPOS to terminal;
• payment status to return to the till;
• card payments to be associated with the correct sale;
• refund information to be connected to original transactions;
• staff to avoid manually entering payment values;
• centralised reporting;
• easier end-of-day reconciliation; and
• more consistent payment processes across locations.

For larger businesses, the operational benefit can be as important as the transaction rate.

Why Does Card Machine Compatibility Matter?

Because the payment estate can contain technology supplied by several different companies.

A typical setup might involve:

EPOS provider → payment integration → terminal → acquiring provider → card scheme → customer's bank.

The fact that two businesses both support card payments does not mean their systems automatically communicate with each other.

Before selecting a new provider, establish exactly where the integration sits.

What Should You Check Before Choosing an Integrated Card Machine?

We would start with these questions:

• Which EPOS platform does the business currently use?
• Which payment providers does that EPOS platform support?
• Which terminal models are supported?
• Does the integration support countertop and portable terminals?
• Does it support pay-at-table?
• Does it support tipping?
• How are refunds handled?
• How are split bills handled?
• How is transaction data reconciled?
• Does it work across multiple sites?
• Can different MIDs be used?
• How are outages handled?
• Who supports the integration when something goes wrong?

Get these answers before signing the merchant-services agreement.

Can Any Card Machine Work With Any EPOS System?

No.

This is one of the most important points on this page.

Compatibility can depend on:

• EPOS software;
• payment provider;
• acquiring relationship;
• terminal manufacturer;
• terminal model;
• integration software;
• API or connector;
• operating system;
• business location; and
• features required by the merchant.

A terminal might technically be capable of accepting Visa, Mastercard and contactless payments but still not work with the merchant's existing till integration.

Card Acceptance and EPOS Compatibility Are Different Questions

A modern payment terminal may support:

• chip and PIN;
• contactless cards;
• Apple Pay;
• Google Pay; and
• other supported payment methods.

That does not tell you whether it integrates with:

• your till;
• your restaurant-management software;
• your booking system;
• your hotel software;
• your stock system; or
• your finance platform.

Payment-method compatibility and software compatibility should therefore be reviewed separately.

Can You Change Card Machine Provider and Keep Your Existing EPOS?

Potentially, yes.

But this needs to be established before changing provider.

There are several possible outcomes.

1. Existing EPOS Already Supports the New Provider

This is often the simplest route.

The new terminals can potentially be configured through an existing supported integration.

2. EPOS Supports the Provider but Requires a Different Integration

The merchant may need:

• new configuration;
• a software update;
• new terminals;
• integration licences;
• testing; or
• support from the EPOS provider.

3. EPOS Does Not Support the New Provider

The merchant then needs to decide whether to:

• choose another payment provider;
• use the terminal in standalone mode;
• develop another integration where possible;
• change EPOS provider; or
• rethink the wider payment architecture.

4. An Existing Integration Is Being Withdrawn

This can also happen.

A previously supported relationship between a payment provider and EPOS platform may change.

We have already seen this issue in the UK market. See our recent article on Epos Now and Dojo no longer integrating.

Do Not Sign the Card Machine Contract Before Checking EPOS Compatibility

This sounds obvious, but it is a common commercial problem.

A merchant negotiates an attractive processing rate.

Then, after signing, discovers:

the new terminals do not integrate with the existing EPOS system.

The business then has three poor options:

• run the card machines standalone;
• pay for additional development or software;
• try to exit the newly signed agreement.

The correct order is:

requirements → compatibility → commercial comparison → contract → implementation.

Not:

cheap quote → sign → discover compatibility later.

Why Integrated Payments Matter for Restaurants

Restaurants and hospitality businesses are one of the clearest use cases for integrated terminals.

Useful functionality can include:

• pay-at-table;
• portable terminals;
• tipping;
• split bills;
• table references;
• EPOS integration;
• automatic payment values;
• refund management;
• centralised reporting; and
• multiple venues.

If a hospitality group changes payment provider, it should establish whether those features continue to work in the replacement setup.

A cheaper rate is not a meaningful saving if staff need to return to manually entering every bill into the terminal.

Why Integrated Payments Matter for Retail

Retail businesses may use integrated terminals to connect:

• sales;
• payments;
• stock;
• returns;
• refunds;
• customer records;
• staff activity;
• locations; and
• financial reporting.

For multi-location retailers, payment-provider choice can therefore become a wider infrastructure decision rather than a terminal purchase.

See our Merchant Services for Multi-Location Retailers guide.

Integrated Card Machines for Multi-Site Businesses

A multi-site business should think at estate level rather than terminal level.

Questions include:

• Can every location use the same terminal estate?
• Can each store or venue have its own MID where required?
• Can transactions be reported centrally?
• Can head office see all settlements?
• Can locations be added easily?
• Can terminals be remotely configured?
• How are replacement devices deployed?
• Can the same EPOS integration operate across all sites?
• What happens if one location loses connectivity?
• Who supports the estate?

The cheapest per-terminal rental may be largely irrelevant if the infrastructure is difficult to manage across 20, 50 or 100 locations.

What Is Semi-Integrated Payment Processing?

Businesses may encounter the term semi-integrated payments.

Broadly, this describes an architecture where the business software and payment terminal communicate about the transaction without the merchant's core EPOS application necessarily handling the underlying cardholder data itself.

The exact architecture varies by provider.

This can allow the merchant's software to initiate and receive payment information while sensitive card processing remains within specialist payment components.

For merchants, the important questions are:

• what information passes between systems;
• which system handles cardholder data;
• how the integration is secured;
• which system stores tokens;
• what happens when the provider changes; and
• how the architecture affects PCI DSS scope.

Can EPOS Integration Reduce Manual Errors?

Potentially, yes.

Without integration, a member of staff might accidentally enter:

£56.70

into the till but:

£65.70

into the card machine.

An integrated payment flow can remove that manual step.

This can help reduce:

• incorrect payment values;
• till/card discrepancies;
• manual reconciliation;
• staff mistakes; and
• end-of-day investigation.

The benefit becomes more significant as transaction volumes increase.

Integration Can Be Worth More Than a Small Rate Saving

Imagine a business processing £250,000 per month.

Provider A offers a slightly cheaper transaction rate but requires standalone terminals.

Provider B costs an additional:

0.03%.

On £250,000 monthly volume, that difference is:

£75 per month.

If integration saves several hours of reconciliation, reduces payment errors and improves staff efficiency across multiple locations, the £75 difference may be commercially insignificant.

This is an illustrative MAS calculation, not a provider-pricing benchmark.

MAS View

Payment cost should include the operational cost of the payment process, not just the acquiring rate.

What Happens to Integration When You Change Provider?

Before migrating, document the existing payment flow.

That should include:

• EPOS provider;
• terminal provider;
• acquirer;
• gateway or payment connector;
• terminal model;
• MIDs;
• locations;
• refund process;
• settlement process;
• reporting;
• user permissions;
• network requirements;
• PCI arrangements; and
• support contacts.

Then compare the proposed new environment against it.

This identifies which parts of the payment estate actually need to change.

Do You Need New Card Machines When Switching Provider?

Sometimes.

A terminal may be physically capable of processing payments but still be configured for a particular provider or terminal-management environment.

Whether it can be reused depends on the hardware, provider, configuration, ownership and acquiring setup.

Businesses should confirm:

• who owns the terminal;
• whether it is rented;
• whether it must be returned;
• whether the new provider supports the model;
• whether it can be securely reconfigured; and
• whether doing so is commercially worthwhile.

Do not assume that owning the physical terminal means it can automatically be used with any payment provider.

Check the Card Machine Contract Separately

The acquiring agreement and terminal contract may not be the same agreement.

This matters when changing provider.

The Payment Systems Regulator found that POS-terminal contracts could discourage businesses from switching acquiring provider, including cases where merchants faced long contracts or potential early-termination charges.

For contracts within the scope of Specific Direction 16, relevant providers must limit the initial term of POS-terminal hire contracts to 18 months before moving to a rolling arrangement.

Read the Payment Systems Regulator's POS-terminal guidance.

See our Merchant Services Contract Renewal guide before signing or exiting an arrangement.

Who Supports the Integration When Something Goes Wrong?

This is one of the most underrated questions in provider selection.

Imagine:

The till is working.

The card machine is working.

But the two have stopped communicating.

Who fixes it?

Potential parties might include:

• EPOS provider;
• payment provider;
• terminal provider;
• integration vendor;
• IT support company; or
• merchant's own technical team.

Before implementing integrated payments, establish:

• who owns first-line support;
• who diagnoses integration failures;
• what the escalation route is;
• support hours;
• expected response times;
• whether remote diagnosis is available; and
• what happens outside normal business hours.

This is particularly important for hospitality, retail and businesses that trade evenings and weekends.

What Happens If the EPOS Integration Fails?

Businesses should have a contingency plan.

Depending on the setup, that may include:

• standalone terminal mode;
• alternative connectivity;
• secondary terminal;
• mobile terminal;
• payment links;
• Tap to Pay;
• alternative checkout process; or
• another agreed fallback payment method.

The objective is not to create unnecessary duplicate infrastructure.

It is to understand how the business continues taking payments when one component fails.

See our Card Machine Connectivity guide.

Does an Integrated Card Machine Need Internet Access?

Most modern integrated payment environments require network connectivity, although the exact connectivity options depend on the terminal and provider.

These may include:

• Ethernet;
• Wi-Fi;
• mobile data / 4G;
• Bluetooth for certain devices; or
• multiple connectivity methods.

For businesses where payment availability is critical, resilience should be part of the terminal decision.

A beautifully integrated solution that fails whenever the venue Wi-Fi has a problem is not necessarily the right solution.

Does Changing Integration Affect PCI DSS?

Potentially.

Changing payment provider does not automatically change PCI DSS scope.

Changing the way payment data interacts with the merchant's systems might.

For example, moving between:

• standalone terminals;
• integrated terminals;
• validated point-to-point encryption solutions;
• MOTO environments;
• payment links;
• merchant-controlled payment applications; or
• other architectures

can create different PCI DSS considerations.

The business should understand how cardholder data moves through the proposed new environment before implementation.

See our PCI DSS When Changing Payment Provider guide and our wider PCI DSS Compliance Guide.

What About Point-to-Point Encryption?

Some integrated terminal environments use point-to-point encryption technologies designed to protect account data between the payment terminal and the secure decryption environment.

Where a PCI-listed validated P2PE solution is used correctly, it can potentially reduce the merchant's PCI DSS scope.

However, merchants should confirm:

• whether the solution is actually PCI-listed;
• which terminal models are included;
• whether the exact implementation is covered;
• what merchant responsibilities remain; and
• what happens if terminals or integrations are changed.

Do not assume that because a provider uses the word “encrypted”, the implementation automatically qualifies as a PCI-listed P2PE solution.

Can One EPOS System Work With Multiple Payment Providers?

Potentially.

Some EPOS platforms support several payment providers or integration partners.

Others have a narrower list.

This can materially affect future provider choice.

A business selecting an EPOS platform should therefore ask:

“Which payment providers can we use today?”

and:

“What happens if we want to change acquiring provider in two years?”

This can be particularly important for growing businesses because locking the till and payment provider too tightly together can reduce commercial flexibility later.

Should Your EPOS Provider Choose Your Payment Provider?

Not automatically.

An EPOS provider may have:

• preferred integrations;
• commercial partnerships;
• technical advantages with particular providers; or
• its own payment proposition.

Those options may be excellent.

But businesses should still understand:

• the transaction pricing;
• acquirer;
• contract;
• settlement;
• terminal costs;
• payment functionality;
• support;
• provider portability; and
• whether alternatives are technically available.

Convenience and commercial competitiveness are not necessarily the same thing.

What About Refunds When Changing Integrated Payment Provider?

A provider migration should include a plan for historic transactions.

Businesses may still need the old system for:

• refunds;
• chargebacks;
• historic reporting;
• settlement queries;
• transaction evidence; and
• accounting reconciliation.

Do not close the old provider before establishing how historic refunds and transaction records will be handled.

How Should a Business Test a New Integrated Card Machine?

Before full rollout, test more than a basic sale.

The test plan should consider:

• standard purchase;
• contactless payment;
• chip and PIN;
• mobile wallet;
• refund;
• partial refund where supported;
• declined transaction;
• cancelled transaction;
• tipping where relevant;
• split payment where relevant;
• different locations;
• settlement reporting;
• EPOS reporting;
• connectivity failure;
• terminal restart;
• end-of-day processes; and
• support escalation.

A successful £1 test transaction does not prove the whole payment environment is ready.

Integrated Card Machine Checklist

Before choosing or changing provider, establish:

• current EPOS provider;
• current payment provider;
• current acquirer;
• terminal models;
• number of terminals;
• number of locations;
• supported payment integrations;
• required terminal type;
• pay-at-table requirements;
• tipping requirements;
• refund process;
• MID structure;
• reporting requirements;
• settlement;
• connectivity;
• PCI DSS architecture;
• fallback payment process;
• integration support ownership;
• current contract end date;
• terminal-contract obligations; and
• future payment-provider options.

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The MAS Integrated Payments Fit Test

Rather than comparing terminals in isolation, Merchant Advice Service would look at six areas.

1. EPOS Fit

Does the payment provider have a proven, supported integration with the merchant's current EPOS system?

2. Operational Fit

Does the setup support the way the business actually trades, including tills, tables, locations, refunds and staff?

3. Technical Fit

How do the terminal, connector, EPOS, network and payment provider communicate?

4. Commercial Fit

How do transaction costs, terminal costs, integration costs and contracts compare?

5. Resilience Fit

What happens if the internet, EPOS integration or terminal stops working?

6. Future Fit

Can the business change provider, add locations or alter payment architecture without replacing its entire EPOS estate?

MAS View

The best integrated card machine is not simply the terminal that works with your EPOS today. It is the payment architecture that works today without unnecessarily restricting your options tomorrow.

How Merchant Advice Service Approaches Integrated Card Machines

Merchant Advice Service helps businesses compare card-payment providers based on the wider payment requirement rather than terminal hardware alone.

When reviewing an integrated payment setup, we may consider:

• existing EPOS;
• current payment provider;
• current acquiring relationship;
• processing volume;
• number of locations;
• number of terminals;
• terminal type;
• transaction fees;
• settlement;
• integration requirements;
• reporting;
• refund processes;
• PCI implications;
• contract position;
• support requirements; and
• future growth.

Our role is to help establish which payment-provider options fit the complete business requirement before the merchant commits to new terminals or contracts.

Explore payment providers through The Payments Directory® or read How Merchant Advice Service Works.

Sources & Further Reading

Payment Systems Regulator — POS Terminal Contracts

The Payment Systems Regulator found that POS-terminal contracts could create barriers to merchants switching card-acquiring provider and introduced measures designed to improve merchant flexibility.

PSR — Note to Point-of-Sale Terminal Providers

Payment Systems Regulator — Card-Acquiring Market Review

The PSR's market review identified POS-terminal contracts, card-acquiring contracts and difficulty comparing providers as factors restricting merchants' willingness and ability to search and switch.

PSR Card-Acquiring Market Review — Final Report

PCI Security Standards Council

PCI SSC publishes the current PCI DSS requirements and standards relevant to merchant payment environments.

PCI SSC Document Library

Related Merchant Advice Service Guidance

• Card Machine Costs UK 2026
• Card Machine Transaction Fees
• Epos Now & Dojo Integration Changes
• Portable Card Machines
• Countertop Card Machines
• Card Machine Connectivity Issues
• Merchant Services for Multi-Location Retailers
• Merchant Services Contract Renewal
• PCI DSS When Changing Payment Provider
• PCI DSS Compliance Guide
• Compare UK Payment Providers
• The Payments Directory®

Editorial & Commercial Disclosure

Merchant Advice Service is an independent payments information, comparison and provider-matching service.

MAS may receive commission or a referral fee from some payment providers where a business chooses to proceed following an introduction. This does not determine the factual information or provider-selection principles included in this guide.

Card-machine and EPOS compatibility varies by provider, terminal model, software version, integration, acquiring arrangement and individual merchant setup.

A terminal supporting a particular card type or payment method does not mean that it automatically integrates with every EPOS or business-management platform.

Businesses should obtain written confirmation of compatibility from the relevant payment and EPOS providers before entering a new contract or beginning a migration.

Changing payment architecture can affect PCI DSS responsibilities. Formal PCI DSS scope and validation requirements should be confirmed with the relevant acquiring provider or appropriately qualified PCI professional.

References to integration benefits are general and do not guarantee reduced errors, lower costs or operational savings for an individual merchant.

Provider integrations, terminal models, software compatibility, contracts and technical capabilities can change.

Merchant Advice Service does not guarantee provider acceptance or technical compatibility.

Integration and regulatory information last checked: 27 August 2026

This guide provides general payments information and should not be treated as technical, legal, regulatory or PCI compliance advice.