Your GPS tracker hasn't updated in hours. The last known location is from yesterday. Here is how to figure out what went wrong — and fix it.

GPS trackers go offline for predictable reasons. From the support cases we handle every week at Lemon Mobile, the cause is almost always one of seven things. This guide walks through each — what it looks like, how to confirm it, and how to fix it.

Quick triage — is it the tracker, the SIM, or the network?

Before working through specific causes, run this 30-second test:

1. Remove the SIM from the tracker.
2. Insert it into a spare mobile phone.
3. Check if the phone can browse the web on mobile data (turn off Wi-Fi first).

If the phone gets mobile data → the SIM is fine. The tracker is the problem.
If the phone cannot get mobile data → the SIM is the problem (expired, network incompatibility, or configuration).

This single test eliminates half of all troubleshooting paths in 30 seconds. We run it before anything else when a customer contacts us.

The 7 most common causes of a GPS tracker going offline

1. SIM expired or inactive

Standard prepaid SIM cards from major Australian and New Zealand carriers expire after 28 to 365 days of inactivity. For GPS trackers that sit in a vehicle or asset for months between recharges, this creates a silent failure — the tracker goes offline the day the SIM expires, often without any notification to the owner.

How to recognise it: Tracker was working fine, then suddenly stopped. No software changes. No physical damage. Time since last recharge is approaching or exceeding the SIM provider's inactivity threshold.

How to fix (short-term): Top up the existing SIM if possible.

How to fix (long-term): Replace with a SIM designed for unattended deployment. Multi-year prepaid SIMs avoid this failure mode entirely — one payment can cover 1 to 8 years of tracker operation without recharges.

2. Tracker only supports 2G or 3G

Australia's 3G networks have been retired. New Zealand has also shut down its 3G networks. A large portion of older GPS trackers — especially budget models sold before 2022 — only support 2G or 3G connectivity. These trackers can no longer connect to Australian or New Zealand mobile networks, regardless of the SIM card used.

How to recognise it: Tracker is more than a few years old. Specifications list "2G" or "3G" or "GSM" without mention of "4G" or "LTE". Tracker has never worked since the 3G shutdown date in your region. No SIM combination works.

How to fix: Replace the tracker with a 4G LTE compatible model. There is no SIM workaround — the hardware itself cannot reach a modern Australian or New Zealand network.

When buying a replacement, look for "4G LTE" in the specifications. Avoid trackers labelled only "Cat-M1" or "NB-IoT" unless you confirm with your SIM supplier that these protocols are supported — most consumer SIMs are standard 4G LTE only.

3. Reporting interval set too long

This one fools many owners into thinking their tracker is broken when it is working perfectly. Most GPS trackers have a configurable reporting interval — how often the tracker sends its location to the server. If this is set to, say, every 5 minutes, the tracker will appear "offline" or "not updating" between reports.

How to recognise it: Tracker updates intermittently, not in real time. Updates often line up with multiples of a particular interval (every 5, 10, or 30 minutes). Position is accurate when it does update.

How to fix: Check your tracker's reporting interval setting (usually via app, SMS command, or web portal). For most use cases, intervals of 10 to 60 seconds give a near-real-time experience. Shorter intervals use more data — match the interval to your actual monitoring needs.

Note that more frequent reporting drains battery faster on battery-only trackers. For hardwired vehicle trackers, this is rarely a concern.

4. Poor cellular coverage at the tracker's location

A tracker can be fully functional with a fully working SIM and still go offline if it sits in an area without cellular signal. Common offline zones include rural farms outside main carrier coverage, underground car parks, metal-roofed sheds, and remote routes used by caravans or freight.

How to recognise it: Tracker reports normally when in town or near built-up areas. Goes offline as soon as it moves to a specific rural location. Other devices in the same area also struggle with mobile data.

How to fix:

• Check your SIM provider's coverage map for your specific area.
• Use a multi-network SIM that can switch between carriers — for example, Telstra + Optus in Australia, or Spark + 2degrees in New Zealand. Broader network access often means reaching tracker locations that a single carrier cannot.
• For deep remote areas with no cellular coverage at all, the only option is a satellite-based tracker (these have very different ongoing costs and are usually not consumer products).

5. Power problems

If the tracker is not getting power, it cannot report anything — and from the user's view, the symptom is identical to a connection problem.

How to recognise it: Tracker has never reported, even briefly, since installation. No LED indicators visible. Hardwired tracker stopped reporting around the same time the vehicle's battery was disconnected, replaced, or worked on. Battery-only tracker has not been charged for an extended period.

How to fix:

• Check wiring — many vehicle trackers fail simply because a kill-switch was activated or a fuse blew.
• Verify constant power vs ignition-only power if the tracker should report when the vehicle is off.
• For battery-only trackers, charge fully and re-test.
• Check for tracker damage from water, heat, or impact.

6. Incorrect APN settings

The APN (Access Point Name) tells your tracker how to connect to the mobile data network. If it is set incorrectly, the tracker has cellular signal but cannot send or receive data — it appears offline even though the SIM and network are both fine.

How to recognise it: The tracker shows signal bars (LED indicator, sometimes via the app) but never updates location or status. The SIM works in a phone with proper APN. Often appears immediately after first setup or after swapping SIMs.

How to fix: Set the APN to the value provided by your SIM card supplier. For Lemon Mobile GPS Tracker SIMs in Australia and New Zealand, the APN is mobile (lowercase, no spaces). Username and password fields should be left blank.

APN configuration varies by tracker model — some require SMS commands, some have a web portal, some auto-detect. Refer to your tracker's manual for the specific procedure.

7. Tracker configuration or firmware issues

Less common, but worth checking after the above are eliminated: the tracker may have configuration errors (server URL set incorrectly, port wrong, account not linked) or firmware issues that prevent reporting. New trackers may need initial setup commands that were never sent.

How to recognise it: Tracker has signal and data connection (verified via SIM tested in phone) but never reports to the expected platform. Setup was rushed or incomplete. Tracker model is new to you and configuration steps were not fully understood.

How to fix: Re-run the tracker's initial configuration. Check the manual for required SMS commands or app settings. For trackers connected to a third-party platform (rather than the manufacturer's own app), verify the server URL, IMEI registration, and account linkage are all correct.

Real cases we've worked through

These are recent examples from our support inbox. Each shows the same diagnostic pattern: identify the cause, apply the fix, restore the tracker.

Case 1 — SinoTrack ST-915L not updating while driving

• Issue: Tracker showed as online but the location did not update during a long trip.
• Cause: Reporting interval was set to 60 seconds, so the dashboard appeared stale between updates.
• Fix: Reduced the reporting interval to 10 seconds.
• Result: Near-real-time tracking restored. Owner was monitoring app refresh rate, not actual tracker failure.

Case 2 — Teltonika FMC920 offline after SIM swap

• Issue: Tracker worked with original SIM, went offline immediately after swapping to a new SIM.
• Cause: Configuration was carried over from the previous setup and did not match the new SIM provider's requirements.
• Fix: Updated the configuration to the new SIM provider's settings.
• Result: Tracker reconnected within 2 minutes.

Case 3 — Older SinoTrack ST-902 stopped working in 2024

• Issue: Tracker that had run reliably for years suddenly went offline and would not reconnect with any SIM.
• Cause: ST-902 only supports 3G. The Australian 3G network had been retired.
• Fix: No SIM workaround possible. Owner upgraded to a 4G LTE tracker.
• Result: Connectivity restored on new hardware. The old tracker had reached the end of its usable life.

Case 4 — Vending machine telemetry dropping out

• Issue: Connected vending machine in a regional town reported intermittently — fine some days, offline others.
• Cause: Single-carrier SIM with weak coverage at the specific machine location. The carrier's signal dropped during peak hours.
• Fix: Switched to a multi-network SIM with access to a second carrier.
• Result: Connection became stable. The site had a coverage gap on one carrier that the second carrier filled.

The patterns we see most often: expired or single-carrier SIMs, older 3G-only hardware, reporting intervals confused for outages, and coverage gaps in regional areas. We will continue updating this guide with new cases as they come in.

GPS tracker offline troubleshooting checklist

Work through these in order. Most offline issues are resolved within the first three steps.

1. Move the SIM into a spare phone — does it get mobile data?
2. Confirm the tracker supports 4G LTE (not 2G or 3G only).
3. Check the SIM has not expired or run out of data.
4. Confirm the tracker has power and the wiring is intact.
5. Check the reporting interval setting in the tracker configuration.
6. Test the tracker in an area with strong cellular signal.
7. Verify the APN setting matches your SIM provider's instructions.
8. Verify the server URL and IMEI registration in the tracking platform.
9. If none of the above resolves the issue, contact your SIM provider with the tracker model and SIM number — many issues can be diagnosed remotely with this information.

If your tracker went offline because of SIM expiry

This is one of the most common causes we see — and it has a structural fix, not just a workaround.

Standard prepaid SIM cards from major carriers expire after 28 to 365 days of inactivity. GPS trackers, by contrast, often stay installed in vehicles, assets and equipment for years. The mismatch between SIM expiry cycles and tracker deployment lifecycles makes silent SIM expiry one of the leading causes of trackers going offline without warning.

The fix is to use a SIM designed for the actual lifecycle of a GPS tracker:

• One-time payment for 1 to 8 years. No monthly recharges, no expiry surprises.
• APN: mobile — same value across every plan, so setup is consistent.
• Multi-network access — Telstra + Optus in Australia, Spark + 2degrees in New Zealand. The tracker can connect via whichever network reaches its location, which often resolves coverage-gap offline issues in the same SIM swap.

If your last tracker outage was caused by SIM expiry, switching to a multi-year SIM eliminates the recurring failure pattern. You set it once, and it stays online for the planned duration without admin overhead.

Find the right plan for your tracker here:

• → GPS Tracker SIM Card Australia — Telstra + Optus 4G, 1 to 8 years validity, one-time payment.
• → GPS Tracker SIM Card New Zealand — Spark + 2degrees 4G, 1 to 8 years validity, one-time payment.

Frequently asked questions

Why has my GPS tracker stopped updating?

The most common causes are an expired prepaid SIM, a tracker that only supports 2G or 3G (now shut down in Australia and New Zealand), a reporting interval set too long, poor cellular coverage at the tracker's location, power supply problems, or incorrect APN settings. Run the SIM test in a spare phone first — it eliminates half of all troubleshooting paths in 30 seconds.

Can a SIM card cause my GPS tracker to go offline?

Yes. A SIM card causes a GPS tracker to go offline when the SIM expires, when its plan runs out of data, when the APN is misconfigured, or when the SIM is from a network that no longer supports the tracker's cellular technology (such as 2G or 3G).

Does the 3G network shutdown affect GPS trackers in Australia?

Yes. Australia's 3G networks have been retired. GPS trackers that only support 2G or 3G can no longer connect to Australian mobile networks. These trackers must be replaced with 4G LTE compatible models. New Zealand has also retired its 3G networks.

What APN should I use for a GPS tracker in Australia?

APN settings vary by SIM provider. For Lemon Mobile GPS Tracker SIMs, the APN is mobile (lowercase, no spaces). Username and password fields should be left blank. Always check with your SIM provider for the correct APN.

How do I know if it's the tracker or the SIM card that's broken?

Move the SIM to a mobile phone. If the phone connects to the mobile data network, the SIM is working — the tracker is the problem. If the phone cannot connect, the SIM has expired or has an APN/configuration issue. This 30-second test isolates the cause faster than any other diagnostic.

Will a multi-network SIM fix offline tracker problems?

A multi-network SIM helps when offline issues are caused by single-carrier coverage gaps. By accessing more than one network, the tracker can connect to whichever carrier reaches its location. Multi-network SIMs do not fix offline issues caused by 3G-only trackers or device configuration problems.