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EFTPOS Not Working? Addressing the Cause Retailers Miss

Written by Lorin McDowell | Feb 20, 2026 1:46:25 AM

When an EFTPOS terminal stops working mid-transaction, everything pauses. The customer waits, the queue builds, and staff scramble to process the payment another way or troubleshoot on the spot. No matter how often this happens, this leaves money on the table.

Most merchants troubleshoot the obvious things first (restarting the terminal, checking cables, or calling their provider). But if the same issues keep coming back, the problem is often deeper than the device itself. In many retail environments, the often-overlooked cause is the mobile connectivity within the building.

This article discusses why EFTPOS terminals fail in store environments and what retailers can do when a restart isn't the fix (spoiler alert: it'sbetter in-building coverage).

Common Reasons EFTPOS Terminals Stop Working

EFTPOS errors can be triggered by a range of issues. Some are device-related, but many trace back to the terminal-to-network connection.

1. Power and Hardware Issues

Sometimes an EFTPOS machine simply needs a charge, a restart, or a replacement cable. If the terminal screen is unresponsive, the battery is flat, or the device won't power on, these are worth checking first.

Basic hardware troubleshooting includes:

  • Ensuring the terminal is securely connected to its power source or base
  • Checking that cables aren't damaged or loose
  • Performing a restart if the terminal is frozen or showing an error
  • Confirming the device firmware is up to date

These are the steps your payment provider will typically walk you through. They're important, but they may only explain part of the picture.

2. Connectivity Failures

For retailers experiencing recurring EFTPOS issues, connectivity is usually the root cause. Every EFTPOS terminal needs a stable connection to process a transaction (whether that's Wi-Fi, Ethernet, or mobile (cellular) data). When that connection drops or becomes unstable, the terminal either throws an error or falls back to offline mode.

That can look like:

  • A transaction failing partway through because the data connection drops out
  • Wi-Fi congestion causing timeouts during payment processing
  • The EFTPOS machine toggling between connected and offline throughout the day
  • A carrier-level outage or network issue that takes the terminal down entirely

If your terminal works fine in one part of the store but not another, or works some days and not others, the problem is more likely the connection than the device.

3. Poor Mobile Signal Inside the Building

Many modern EFTPOS terminals rely on mobile connectivity (4G/5G) rather than a fixed internet line. That works well in areas with a strong signal. But inside commercial buildings, mobile signals often degrade due to the building's structure.

Common blockers include:

  • Reinforced concrete, steel framing, and dense walls
  • Energy-efficient (Low-E) glass
  • Internal layouts that create shielded zones
  • Basements, back-of-house areas, or lower-ground retail spaces

From the outside, carrier coverage might look fine. But once the signal passes through layers of building material to reach your EFTPOS terminal, it can weaken enough that transactions fail or time out.

This is one of the most overlooked causes of EFTPOS problems in retail, and one of the hardest to diagnose from the terminal alone.

The Business Impact of Unreliable EFTPOS

When an EFTPOS terminal isn't working, the immediate impact is obvious: a transaction can't be processed. But for retailers, the consequences extend beyond a single failed payment.

  • Lost sales: Some customers won't wait for a fix. If they can't tap and pay, they may abandon the purchase entirely. The RBA reported in October 2024 that 44% of in-person tap-to-pay transactions in Australia were made by mobile device, meaning the volume of cashless payments at risk is significant.
  • Customer frustration: Repeat payment failures erode trust. Customers expect fast, seamless checkouts, and even occasional EFTPOS issues can leave a poor impression.
  • Staff workarounds: When terminals aren't reliably connected, staff start improvising (processing transactions offline, writing down card details, or sending customers to another terminal). These workarounds introduce inefficiency and, in some cases, security and compliance risk.
  • Operational drag: Time spent troubleshooting EFTPOS connectivity is time not spent serving customers. For high-traffic retail environments, that adds up quickly.

When the Fix Isn't the Terminal: It's the Coverage

If you've already checked the basics (restarted the terminal, confirmed your internet connection, contacted your provider) and the issues persist, it's worth checking the mobile coverage in your building.

Poor in-building mobile signal is a common root cause of EFTPOS failures in retail, particularly in:

  • Shopping centres and large retail venues
  • Stores with thick walls, concrete, or steel construction
  • Basement-level and underground retail spaces
  • Back-of-house and storage areas where terminals are also used

The challenge is that this type of issue doesn't always appear as a clear error in the terminal. It often presents as intermittent dropouts, slow transaction processing, or devices that toggle between connected and offline throughout the day.

How In-Building Coverage Solutions Fix the Problem

In-building coverage (IBC) systems are designed to deliver a reliable mobile signal into spaces where the external network can't reach effectively.

Signal Boosters

A mobile signal booster captures an existing signal from outside the building, amplifies it, and redistributes it indoors through internal antennas. For smaller retail sites with a specific problem zone, this can be a practical, cost-effective fix.

Distributed Antenna Systems (DAS)

For larger retail environments such as shopping centres, multi-level venues, or sites with widespread dead zones, a DAS provides engineered coverage across the entire premises. It uses a network of antennas to ensure a consistent signal throughout the building, including areas where EFTPOS connectivity typically drops out.

Compliance in Australia

In Australia, signal boosting equipment must meet ACMA standards and comply with carrier requirements. Non-compliant installations can cause network interference and regulatory issues. A professional site assessment ensures the solution is properly designed, carrier-aligned, and fit for your specific building.

What Retailers Should Do Next

If your EFTPOS terminals keep dropping out and basic troubleshooting hasn't resolved the issue, it's worth investigating the mobile signal environment inside your store.

A site audit will identify where coverage breaks down, what's causing it, and what solution will deliver reliable connectivity, not just for EFTPOS, but for every device and process that depends on mobile signal indoors.

MobileCorp is an Australian in-building mobile coverage specialist. We work with retailers, venues, and commercial operators to diagnose coverage failures, design the right IBC or DAS solution for the site, and manage the full process, from site assessment to installation. If your EFTPOS terminals are dropping out and basic troubleshooting hasn't fixed it, we can help you find and resolve the underlying connectivity issue (without disrupting normal business).

Address EFTPOS Not Working

FAQs

Why does my EFTPOS terminal keep losing its connection?

Repeat connectivity issues are often caused by weak or inconsistent mobile signals inside the building. If the terminal relies on cellular data, building materials like concrete, steel, and Low-E glass can reduce the signal to the point where transactions fail or time out.

Can poor mobile coverage really cause EFTPOS failures?

Yes. Many EFTPOS terminals use mobile data (4G/5G) to process transactions. If the in-building mobile signal is weak or unstable, the terminal may not stay connected long enough to complete a payment (even if signal bars appear adequate).

What's the difference between a signal booster and a DAS for retail?

A signal booster amplifies an existing outdoor signal into a targeted indoor area. A Distributed Antenna System (DAS) delivers engineered coverage across a larger footprint using a network of internal antennas. DAS is typically better suited to shopping centres, large venues, and multi-level retail environments.

Should I contact my payment provider or my mobile coverage provider?

Start with your payment provider to rule out terminal or account-related issues. If the device is working correctly but connectivity problems persist, the issue is likely the in-building mobile signal, and that's where an in-building coverage specialist like MobileCorp can help.

Do I need carrier approval to install a signal booster in my store?

Yes. In Australia, all signal boosting equipment must meet ACMA requirements and be carrier-compliant. Unauthorised equipment can interfere with networks and may result in penalties.