Card Machine Not Working? Connectivity, Outages & Backup Payment Options

If your card machine stops working, the terminal itself may not actually be the problem.

A failed card payment can be caused by several different parts of the payment environment, including:

• the terminal;
• Wi-Fi;
• Ethernet or the local network;
• mobile connectivity;
• the EPOS integration;
• the merchant's internet connection;
• the payment provider;
• the acquiring platform;
• terminal configuration; or
• the customer's card or issuing bank.

That distinction matters.

Repeatedly rebooting a card machine will not solve an internet outage, and replacing a terminal will not fix a broken EPOS integration.

For businesses where customers depend on card payments, the better approach is to understand where the payment journey can fail and what the business will do when it does.

This is particularly important in 2026 because UK payment connectivity is also moving away from older infrastructure. All UK 3G mobile networks have now been switched off, 2G is being phased out, and the UK's old analogue telephone network is scheduled to be retired on 31 January 2027.

A reliable card machine is therefore not just a terminal that works today. It is a payment setup with suitable primary connectivity, modern infrastructure and a practical backup route when something fails.

Quick Summary

• A card machine failing does not automatically mean the terminal itself is faulty.
• Problems can originate from the terminal, local network, internet connection, mobile network, EPOS integration, payment provider or acquiring platform.
• Businesses should identify whether one terminal, one location or the entire payment estate is affected before troubleshooting.
• Ethernet, Wi-Fi and mobile data each have different strengths and potential points of failure.
• UK 3G mobile networks have now been switched off.
• Older payment terminals relying on 2G may also need upgrading as UK operators withdraw 2G over the coming years.
• Ofcom specifically identifies payment terminals among the devices that may be affected by the 2G switch-off.
• The UK's old PSTN analogue telephone network is scheduled for retirement on 31 January 2027.
• Businesses still using payment terminals or other equipment dependent on analogue telephone lines should review them now.
• Do not assume a Wi-Fi terminal automatically switches to 4G when Wi-Fi fails.
• Offline payment capability varies between providers and can create additional merchant risk.
• Backup options can include secondary connectivity, another terminal, Tap to Pay or another approved payment route.
• High-volume and multi-site merchants should treat payment resilience as part of their payment architecture, not an emergency afterthought.

Find Your New Processor

Why Is My Card Machine Not Working?

Start by identifying the scale of the problem.

Ask:

• Is one terminal affected?
• Are all terminals at the location affected?
• Are other internet-connected systems working?
• Is EPOS working?
• Can the terminal connect outside the EPOS integration?
• Are terminals at other locations still processing?
• Are all cards failing or only one customer's card?
• Is the payment provider reporting an outage?

Those answers can quickly narrow the fault.

MAS View

Before fixing the card machine, identify which part of the payment journey is actually broken.

What Should You Check First When a Card Machine Stops Connecting?

Follow the instructions provided by your payment provider or terminal manufacturer for the specific device.

As a general diagnostic process, check:

1. whether the terminal is powered and functioning;
2. whether the device shows a network or connectivity error;
3. whether other terminals have the same problem;
4. whether the business internet connection is working;
5. whether the relevant Wi-Fi or Ethernet connection is available;
6. whether mobile signal is available if cellular connectivity is used;
7. whether EPOS is working;
8. whether the provider has reported a service incident; and
9. whether restarting the device using the provider-approved process resolves the problem.

Avoid performing undocumented hard resets, removing security components or changing network settings unless instructed by the provider.

Payment terminals are managed payment devices, not ordinary consumer electronics.

Is the Card Machine Faulty or Is the Internet Down?

This is one of the first distinctions to make.

If:

• several terminals stop simultaneously;
• EPOS loses internet access;
• other business systems are offline; or
• the router shows a connectivity problem,

the terminal hardware may be functioning correctly.

Likewise, if:

• every other terminal works;
• the internet is available;
• EPOS is functioning normally; and
• only one device repeatedly fails,

the issue may sit with that terminal, its configuration or its local connection.

What Does “No Network” on a Card Machine Mean?

A message such as:

• No Network;
• Connection Failed;
• Unable to Connect;
• Host Unavailable;
• Network Error; or
• Connection Timed Out

can indicate that the terminal cannot establish the connection required to process the transaction.

However, the exact meaning varies by terminal and provider.

Do not assume identical messages mean the same thing across different terminal models.

Record the exact:

• error message;
• error code;
• time;
• terminal identifier; and
• transaction circumstances.

This can make provider support substantially easier.

How Do Card Machines Connect to the Payment Provider?

Modern terminals can use several connection methods.

Older terminals may also depend on legacy telephone or mobile infrastructure, which deserves particular attention in 2026.

Are 3G Card Machines Still Suitable in the UK?

No new UK terminal deployment should depend on 3G connectivity.

Ofcom confirms that the UK's 3G mobile networks are now switched off.

Vodafone, EE, Three and O2 have all completed their 3G network shutdowns.

That means an older device which depended on 3G needs another supported connection method or replacement hardware.

Read Ofcom's current 2G and 3G switch-off guidance.

MAS View

If your terminal documentation still describes 3G as its primary mobile connection, it is time to establish exactly how that device is now connecting.

What About 2G Card Machines?

2G remains available on some UK networks in 2026, but it is also being phased out.

All UK mobile network operators have committed to withdraw 2G by 2033 at the latest, and individual networks are moving earlier.

Ofcom's current published position includes:

• EE: plans to begin switching off 2G from May 2029;
• O2: plans to begin switching off 2G from summer 2029;
• Vodafone: plans to switch off its UK 2G network during 2030; and
• Three: does not operate a 2G network.

Ofcom specifically identifies payment terminals among the types of equipment that may still depend on 2G and may need upgrading.

The practical point is not that every 2G terminal will stop tomorrow.

It is that a business replacing or deploying terminals now should not build a new payment estate around infrastructure already scheduled for retirement.

Should New Card Machines Support 4G?

Where cellular connectivity is required, businesses should confirm the terminal supports current-generation mobile networks.

Ofcom advises buyers of connected equipment to make sure new devices support at least 4G as legacy mobile networks are withdrawn.

Ask the payment provider:

• Does the terminal support 4G?
• Which network does it use?
• Can it access more than one mobile network?
• Is the SIM domestic or roaming?
• Can the terminal use both Wi-Fi and mobile data?
• How does fallback work?
• What happens if the mobile network is unavailable?
• How will older devices be migrated?

What Is Happening to Card Machines Connected to Old Telephone Lines?

This is another important 2026 issue.

The UK's old analogue Public Switched Telephone Network — PSTN — is due to be retired on 31 January 2027.

Openreach warned businesses in July 2026 that around 350,000 business premises still needed to migrate and specifically identified payment terminals among the operational technologies that can remain dependent on PSTN-connected services.

Read Openreach's July 2026 business warning.

Will an Old Phone-Line Card Machine Stop Working in 2027?

If the device genuinely depends on the old analogue network, the business needs to establish how it will operate after migration.

Do not assume that connecting an old device to a new digital phone service means it will automatically continue working.

Openreach advises businesses with equipment connected to analogue lines to check compatibility with the relevant equipment supplier or service provider.

Read Openreach's digital phone-line guidance.

Check Now If Your Business Still Has:

• older card machines connected to telephone sockets;
• legacy EPOS communication equipment;
• fax machines;
• alarm systems;
• door-entry systems;
• lift alarms; or
• other operational equipment sharing analogue lines.

The migration affects more than voice telephones.

MAS View

The January 2027 PSTN retirement makes “it still works today” a poor test for whether an older card-machine setup is fit for the next contract period.

Why Does My Card Machine Keep Disconnecting From Wi-Fi?

Possible causes include:

• weak signal;
• distance from the access point;
• thick walls;
• basements;
• large premises;
• outdoor trading areas;
• network congestion;
• incorrect Wi-Fi credentials;
• access-point failure;
• network configuration changes;
• DHCP/IP configuration issues;
• software or terminal configuration; or
• the terminal moving between coverage zones.

For portable terminals, test the Wi-Fi where the customer actually pays.

A restaurant terminal that works beside the router but disconnects in the garden, upstairs dining room or private function area does not have adequate payment connectivity.

Should Card Machines Use the Customer Wi-Fi Network?

Businesses should discuss network architecture with their payment, EPOS and IT providers rather than treating payment terminals as ordinary guest devices.

Payment infrastructure should be appropriately managed and secured.

For larger environments, businesses may separate:

• guest Wi-Fi;
• staff systems;
• EPOS;
• payment infrastructure; and
• other operational technology

according to their security and technical architecture.

The exact PCI DSS implications depend on how the payment environment is designed.

See our Card Machine Security & PCI DSS guide.

Is Ethernet More Reliable Than Wi-Fi for Card Machines?

Ethernet can provide a stable connection for a fixed countertop terminal because there is no wireless signal between the device and the local network.

That can make it attractive for:

• high-volume retail tills;
• fixed reception desks;
• trade counters;
• supermarkets; and
• other permanent checkout positions.

However, Ethernet does not eliminate all connectivity risk.

The transaction may still fail because of:

• router failure;
• switch failure;
• internet outage;
• DNS/network problems;
• payment-provider outage;
• EPOS failure; or
• terminal failure.

Wired is not the same as outage-proof.

Should a Card Machine Have 4G Backup?

For some businesses, yes.

A terminal capable of using mobile data when the fixed internet connection fails can add useful resilience.

But confirm how it actually works.

Ask:

• Does the terminal automatically switch connections?
• Does staff intervention need to occur?
• Does the SIM require activation?
• Which mobile network is used?
• Is mobile backup included in the contract?
• Does the EPOS integration continue working during fallback?
• Can the terminal operate standalone if EPOS loses connectivity?

A terminal having a SIM slot does not prove that automatic failover has been configured.

What If the Internet Works but the Card Machines Do Not?

This suggests the problem may sit elsewhere.

Possible causes include:

• payment-provider outage;
• acquirer connection issue;
• terminal configuration;
• firewall/network rule changes;
• EPOS integration problems;
• certificate/software problems;
• terminal-management issue; or
• an individual device fault.

Check whether:

• the provider has a service-status page;
• another location is affected;
• the terminal works standalone;
• other terminal models are affected; and
• a recent software, router, EPOS or network change occurred.

What If the Card Machine Works but EPOS Does Not?

This can be an integration issue rather than a payment-processing outage.

An integrated setup might require:

EPOS → payment connector → terminal → provider.

If the terminal can process a standalone transaction but cannot receive the payment value from the till, investigate the EPOS/payment integration.

The business should know who supports that connection.

Possible parties include:

• EPOS provider;
• payment provider;
• integration vendor;
• merchant IT team; and
• terminal provider.

See our Integrated Card Machines & EPOS Compatibility guide.

Who Should You Call When an Integrated Card Machine Stops Working?

This should ideally be agreed before go-live.

One of the most frustrating payment failures is:

“The till company says call the card provider. The card provider says call the till company.”

During provider selection, establish:

• who owns first-line support;
• who supports the terminal;
• who supports the EPOS connector;
• who supports the local network;
• how incidents are escalated;
• support operating hours; and
• whether one supplier coordinates with another.

This becomes particularly important for businesses trading outside standard office hours.

Can You Reboot a Card Machine?

Rebooting can resolve some temporary issues, but use the method documented by the payment provider or terminal manufacturer.

Do not assume instructions for one terminal apply to another.

In particular, avoid:

• removing components unnecessarily;
• opening the terminal casing;
• performing undocumented factory resets;
• changing security settings;
• installing unauthorised software; or
• altering network configuration without understanding the wider payment setup.

If the terminal is remotely managed, an inappropriate reset could create a larger configuration issue.

Should You Factory Reset a Card Machine?

Not unless instructed by the provider.

A payment terminal can contain provider-specific configuration, security material and merchant settings.

A factory reset is therefore different from simply restarting an ordinary consumer device.

If basic provider-approved troubleshooting does not work, contact technical support.

Can a Low Battery Cause Card Machine Problems?

Potentially.

A portable device with a deteriorating or insufficiently charged battery can become unreliable.

But there is no universal percentage such as “a card machine must have at least 25% battery to process payments”.

Battery behaviour varies by:

• terminal;
• manufacturer;
• device age;
• printing;
• screen usage;
• Wi-Fi/mobile usage; and
• transaction volume.

Follow the manufacturer's charging guidance and replace deteriorating devices or batteries through the approved process.

Does a Card Machine Need a Till Roll to Process Payments?

Not universally.

Some terminals have integrated receipt printers. Others are designed around digital receipts or generate receipts through the EPOS system.

A missing till roll should therefore not be treated as a universal explanation for a failed card transaction.

Check the requirements of the specific device and merchant setup.

Can a Card Machine Process Payments Offline?

Some payment solutions offer forms of offline processing, but merchants should not assume this is available.

Offline or store-and-forward functionality varies significantly between providers.

It can also shift risk to the merchant because the issuer may not have authorised the transaction at the time the customer leaves.

This can potentially create:

• declined transactions when uploaded later;
• fraud risk;
• transaction limits;
• card restrictions;
• merchant liability; and
• reconciliation complexity.

Where offline functionality exists, businesses should understand:

• which transactions qualify;
• value limits;
• time limits;
• which cards are accepted;
• who bears the risk;
• when transactions are uploaded; and
• how failed offline transactions are handled.

MAS View

Offline acceptance is not the same as guaranteed payment.

What Can a Business Use if Card Machines Go Down?

The correct backup depends on what has failed.

The last point is particularly important.

A second terminal from the same provider using the same processing infrastructure may not provide meaningful resilience during a provider-wide outage.

Can Tap to Pay Be Used as a Backup?

Potentially, yes.

A supported smartphone can provide an alternative contactless payment endpoint if traditional terminal hardware fails.

But the backup needs to be prepared in advance.

That means:

• merchant onboarding completed;
• compatible devices available;
• app installed;
• staff trained;
• access permissions configured;
• settlement understood;
• receipts understood;
• transactions tested; and
• the service included in the incident plan.

See our Tap to Pay UK guide.

Can Payment Links Be Used During a Card Machine Outage?

Potentially, depending on the business and provider.

A payment link can allow a customer to complete an online card payment using their own device.

This can be useful in certain service environments, but it may be unsuitable for:

• fast-moving retail queues;
• very high transaction volumes;
• situations where immediate physical checkout is expected; or
• businesses whose internet/payment-provider infrastructure is itself affected.

It should be treated as an alternative payment journey rather than an exact substitute for a working terminal.

Should Every Business Have a Spare Card Machine?

Not necessarily.

The answer depends on the financial impact of payment downtime.

Consider:

• daily card turnover;
• peak-hour turnover;
• number of terminals;
• number of sites;
• availability of alternative devices;
• provider replacement times;
• customer tolerance for alternative payment methods; and
• cost of maintaining backup equipment.

A merchant processing £500 in card sales per day has a different resilience requirement from one processing £50,000 during a busy Saturday.

How Should Restaurants Plan for Card Machine Outages?

Hospitality businesses have a particular problem:

the customer may already have consumed the service before payment is attempted.

A restaurant outage plan might therefore consider:

• Wi-Fi coverage;
• cellular-connected terminals;
• more than one authorised device;
• EPOS fallback;
• Tap to Pay;
• payment links where appropriate;
• support availability during evening/weekend trading;
• staff escalation; and
• how unpaid bills will be handled.

Portable-terminal connectivity should be tested across:

• dining areas;
• bars;
• private rooms;
• terraces;
• beer gardens; and
• other customer-payment areas.

How Should Retailers Plan for Payment Outages?

Retail resilience depends heavily on transaction volume and checkout design.

Questions include:

• Do all tills depend on one internet connection?
• Do terminals have independent connectivity?
• Can tills operate if the EPOS-payment integration fails?
• Can temporary payment points be created?
• Can Tap to Pay be deployed to approved devices?
• Are alternative providers genuinely independent?
• How will transactions be reconciled after recovery?
• Who communicates with stores during an outage?

For a multi-location merchant, resilience should be reviewed at estate level.

What Should Multi-Site Businesses Monitor?

A multi-site merchant should be able to distinguish:

• individual-terminal failure;
• location-level failure;
• regional connectivity failure;
• EPOS-platform failure;
• payment-provider failure; and
• group-wide infrastructure failure.

Useful operational information can include:

• terminal status;
• site connectivity;
• provider status;
• transaction success rates;
• decline patterns;
• incident start time;
• affected locations;
• fallback activation; and
• recovery time.

MAS View

A multi-site merchant should know whether it has lost one terminal, one shop or its entire payment network within minutes — not after stores begin calling head office individually.

Does Having Two Internet Providers Solve Payment Resilience?

It can reduce one type of risk, but not every type.

Two independent broadband connections may help if the problem is the primary internet service.

They will not necessarily help with:

• terminal hardware failure;
• EPOS failure;
• payment-provider outage;
• acquirer outage;
• configuration errors;
• local power failure; or
• an issue shared by both payment routes.

Good resilience identifies individual points of failure rather than simply adding duplicate equipment.

Does Having Two Card Machines Provide a Backup?

Sometimes.

But two terminals are not necessarily two independent payment routes.

If both terminals use:

• the same provider;
• the same acquirer;
• the same internet connection;
• the same EPOS platform; and
• the same integration,

a shared failure could take both offline simultaneously.

Should a Business Use Two Payment Providers?

For some high-volume or payment-critical businesses, multi-provider or multi-acquirer resilience can be worth considering.

But adding a second provider introduces additional complexity, including:

• contracts;
• reconciliation;
• reporting;
• MIDs;
• integrations;
• PCI architecture;
• terminal management;
• refund processes; and
• staff procedures.

The commercial and operational benefit therefore needs to justify the additional infrastructure.

For online and more complex payment architectures, see our guide to acquirer-agnostic and multi-acquirer payment setups.

How Much Can Card Machine Downtime Cost?

The answer depends on turnover and whether customers can use another payment method.

Consider a business processing:

£30,000 of card payments during a ten-hour trading day.

Average hourly card turnover is:

£3,000.

A two-hour payment outage therefore occurs during a period representing approximately:

£6,000 of normal card-payment volume.

That does not mean the merchant automatically loses £6,000 — customers may wait or use another payment method — but it illustrates the commercial exposure.

This is an illustrative MAS calculation, not an estimate of expected outage losses.

MAS View

The value of payment resilience should be compared with the turnover exposed when payments stop.

When Does a Connectivity Problem Become a Provider-Selection Problem?

Occasional technical incidents happen across technology providers.

But repeated problems can indicate the current setup no longer fits the business.

A provider review may be worthwhile where:

• terminal outages are frequent;
• Wi-Fi performance is consistently poor;
• older mobile connectivity is becoming obsolete;
• analogue/PSTN equipment remains in use;
• replacement hardware takes too long;
• support is unavailable during trading hours;
• EPOS integration repeatedly fails;
• the terminal estate is outdated;
• fallback options are inadequate;
• the business has expanded into new locations; or
• the current provider cannot support a more resilient architecture.

At that stage, troubleshooting one machine at a time may be treating the symptom rather than the underlying payment problem.

What Support Should a Card Machine Provider Offer?

Support should reflect the hours the business trades.

Before selecting a provider, establish:

• support opening hours;
• weekend support;
• telephone support;
• incident escalation;
• provider status information;
• remote terminal diagnosis;
• replacement-terminal times;
• EPOS integration support;
• network troubleshooting responsibilities; and
• support for multiple locations.

A hospitality business whose busiest trading period is Friday evening should specifically understand what support exists on Friday evening.

What Information Should You Give Technical Support?

Before contacting support, collect:

• merchant name;
• location;
• terminal identifier;
• terminal model;
• exact error message;
• error code;
• time the issue began;
• whether other terminals work;
• whether other locations work;
• whether internet access is available;
• whether EPOS is functioning;
• connection type;
• recent network/software changes; and
• troubleshooting already completed.

This is much more useful than simply reporting:

“The card machine isn't working.”

What Should Businesses Do Before a Planned Internet Change?

Payment infrastructure should be included whenever the business changes:

• internet provider;
• router;
• firewall;
• Wi-Fi;
• network architecture;
• EPOS;
• business premises; or
• IT provider.

Before the change:

• identify all payment terminals;
• document connection methods;
• confirm required network settings;
• involve the payment/EPOS provider;
• prepare fallback connectivity;
• test after migration; and
• avoid making major network changes immediately before peak trading where possible.

What Should Businesses Do Before the PSTN Switch-Off?

If any payment or EPOS equipment still relies on an analogue telephone line:

1. identify the equipment;
2. identify the supplier;
3. confirm whether it depends on PSTN;
4. ask whether it will work after migration;
5. identify the required replacement or upgrade;
6. test the new connection;
7. update business-continuity procedures; and
8. complete the migration ahead of 31 January 2027.

Do not leave payment-critical equipment until the final weeks of the analogue network.

Card Machine Connectivity Checklist

Businesses should know:

• which connection each terminal uses;
• whether terminals support Ethernet, Wi-Fi or 4G;
• whether any devices still depend on 2G;
• whether any devices depend on analogue telephone lines;
• which mobile network is used;
• where Wi-Fi coverage is weak;
• how connection fallback works;
• whether terminals can operate independently of EPOS;
• who supports the EPOS integration;
• who supports the business network;
• who supports the terminal;
• what happens during provider outages;
• whether spare terminals are available;
• whether Tap to Pay is configured;
• whether alternative payment routes exist;
• how staff recognise an outage;
• who staff contact;
• how transactions are reconciled after recovery; and
• how quickly failed hardware can be replaced.

Find Your New Processor

The MAS Payment Resilience Test

Merchant Advice Service would assess card-machine connectivity across six areas.

1. Primary Connection

How does the terminal normally reach the payment provider — Ethernet, Wi-Fi or mobile data?

2. Local Resilience

What happens if the local internet connection, Wi-Fi or individual terminal fails?

3. Integration Resilience

Can payments continue if EPOS stops communicating with the terminal?

4. Provider Resilience

What happens if the payment provider or acquiring route itself is unavailable?

5. Infrastructure Resilience

Is any part of the payment estate still dependent on retiring 2G, 3G or PSTN technology?

6. Operational Resilience

Do staff actually know how to keep taking payments and escalate the issue when the primary route fails?

MAS View

Payment resilience is not having a spare card machine in a drawer. It is knowing which failure that spare machine can actually solve.

How Merchant Advice Service Approaches Card Machine Connectivity

Merchant Advice Service helps businesses compare payment providers and terminal setups based on the complete payment requirement.

Where connectivity or reliability is driving a provider review, we may consider:

• current terminal estate;
• current payment provider;
• current acquirer;
• processing volume;
• number of locations;
• EPOS;
• Ethernet/Wi-Fi/mobile connectivity;
• legacy 2G or PSTN dependencies;
• provider support;
• replacement processes;
• backup payment options;
• multi-site resilience;
• settlement;
• transaction costs;
• contracts; and
• future payment requirements.

The aim is not simply to replace an unreliable terminal with a newer-looking terminal. It is to identify whether the replacement payment arrangement addresses the underlying cause of the problem.

Businesses can explore providers through The Payments Directory® or read How Merchant Advice Service Works.

Sources & Further Reading

Ofcom — UK 2G and 3G Network Switch-Off

Ofcom confirms that all UK 3G mobile networks have now been switched off. UK mobile operators are also gradually withdrawing 2G, and Ofcom specifically identifies payment terminals among the devices that may be affected.

Ofcom — Switching Off the UK's 2G and 3G Networks

Ofcom — Advice for Connected-Device Suppliers

Ofcom provides current information on the migration of IoT and third-party devices away from legacy mobile networks, including the announced UK 2G withdrawal timetables.

Ofcom — 2G and 3G Switch-Off Advice for Connected Devices

Openreach — PSTN Switch-Off

Openreach is retiring the UK's analogue Public Switched Telephone Network on 31 January 2027 and has highlighted payment terminals among the business technologies that can still depend on legacy lines.

Openreach — Business Warning Ahead of the PSTN Switch-Off

Openreach — Digital Phone Line Migration

Openreach advises businesses to check whether existing devices connected to analogue telephone lines will operate on replacement digital technology.

Openreach — Upgrading to Digital Phone Lines

Ofcom — PSTN Migration

Ofcom confirms BT's planned retirement of the PSTN by 31 January 2027 and continues to monitor the migration from analogue to digital telephone services.

Ofcom — PSTN Switch-Off and VoIP Migration

Related Merchant Advice Service Guidance

• Portable Card Machines
• Countertop Card Machines
• Tap to Pay UK
• Integrated Card Machines & EPOS Compatibility
• Card Machine Security & PCI DSS
• How to Choose a Card Machine Provider
• Card Machine Costs UK 2026
• Card Machine Transaction Fees
• Merchant Services for Multi-Location Retailers
• PCI DSS Compliance Guide
• 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 error messages, restart processes, connectivity functionality, offline-payment capabilities and fallback behaviour vary between terminal models and payment providers.

Businesses should follow the technical instructions supplied by their own terminal and payment provider rather than using generic reset procedures intended for another device.

UK 3G networks are now switched off. UK 2G networks are being phased out, with individual mobile-network operators publishing their own migration schedules. Businesses should confirm the connectivity used by older terminals with their provider.

The UK's analogue PSTN is currently scheduled for retirement on 31 January 2027. Businesses should confirm the compatibility of any payment or operational equipment still connected to analogue telephone lines.

Offline or store-and-forward payments can create additional merchant risk and should only be used in accordance with the relevant provider's rules and controls.

Alternative payment routes, secondary connectivity and backup terminals do not guarantee uninterrupted payment acceptance because different systems may share infrastructure or providers.

Provider functionality, mobile-network schedules, infrastructure dates and technical requirements can change.

Merchant Advice Service does not guarantee provider availability, connectivity, uptime, merchant acceptance or technical compatibility.

Connectivity and infrastructure information last checked: 27 August 2026

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