Critical Issue: Odometer Inconsistency & Identifier Misuse in Mobile App (Impacting Per-KM Payments)

Fahad 3 days ago

Hello Team,

We are using Traccar mobile app with our own hosted server for tracking field employees. Our use case is distance-based reporting, where employee payments are calculated per kilometer traveled.

We have identified a serious data integrity issue that is affecting our reporting and financial calculations.

Problem Summary

For multiple employees, we are observing:

Same device identifier
But completely inconsistent odometer values
Sudden jumps between unrelated odometer ranges

This results in:

Extremely high or incorrect daily distances
Unreliable reports
Financial discrepancies (over/under payments)
Sample Data (Real Case)

Device: 1001487

Date Distance Start Odo End Odo
2026-03-04 8471.7 km 103223.9 111695.7
2026-03-05 49.7 km 4943.0 4992.7
2026-03-11 8459.3 km 154115.7 162575.0
2026-03-14 158.4 km 5415.1 5573.5
2026-03-31 87.1 km 163488.6 163575.8

Observations
Odometer values are not continuous
Multiple odometer “clusters” exist for same device:
~5,000 range
~100,000 range
~160,000 range
Daily distances exceeding 8000 km, which is clearly impossible

Root Cause (Based on Analysis)

We believe the issue is due to:

  1. Identifier Can Be Changed in Mobile App

Users can manually modify the device identifier in the app.

  1. Same Identifier Used on Multiple Phones
    Different phones have different internal odometer values
    All send data under the same identifier
  2. App Reinstall / Reset
    Odometer resets or changes after reinstall

Business Impact

This is a critical issue for us because:

Payments are calculated per kilometer
Incorrect odometer = incorrect payment
Possibility of intentional misuse / manipulation
Loss of trust in tracking system
Questions
Is this behavior expected when using mobile app?
Is odometer meant to be reliable for reporting?
How does Traccar handle multiple devices with same identifier?

Suggested Improvements

We request guidance or possible enhancements:

  1. Restrict Identifier Editing
    Option to disable manual identifier changes in app
  2. Bind Device to Physical Phone
    Lock identifier to device hardware (IMEI / Android ID)
  3. Detect Multiple Devices per Identifier
    Server-side warning if multiple sources detected
  4. Odometer Handling
    Option to ignore device odometer
    Use server-calculated distance instead
  5. Validation Rules
    Flag unrealistic daily distances (e.g., > 300 km)
    Current Workaround

Request

This issue affects real financial calculations and could impact many businesses using mobile tracking.

We would appreciate:

Official clarification
Best practices
Possible feature improvements

Thank you for your support.

Anton Tananaev 3 days ago

You can lock configuration with a password.