Biometric Attendance for Mines in Zambia — Face Clock-In, Offline

Where the wage bill leaks

On a mine, a headcount is money twice.

Contractors are paid for the heads they put on site, and pay the heads they say were there. A padded register costs both ends.

Ghost heads on the roll

A name billed to the principal and paid on payday who was never at the gate. With no face clock-in, a daily-rate worker is paid for no days.

Lent cards and shared PINs

One worker swipes for three. A face and a live blink have to be standing at the device.

No signal at the pit

Remote sites from Solwezi to the Copperbelt lose network. Matching runs on the device and syncs later.

A worker clocking in with their face on an Android device at the site gate

One device at the gate. The whole site clocked.

Enrol each worker once on the Android phone or tablet at the site. From then on they look at it, blink, and are clocked in — and do the same to clock out. Matching runs on the device, so a morning muster of hundreds moves at the pace of a glance, with or without signal.

Blink liveness check — a printed photo or a picture on a screen does not pass
The time comes from the server's clock, not the phone's
GPS coordinates and their accuracy on every clock-in and clock-out
Saved on the device first and sent when signal returns, never twice

Hourly mine workers paid from the hours between face in and face out

Shift hours, measured not written.

Put shift workers on an hourly rate and the pay run pays the hours between their face clock-in and clock-out, measured on the server's clock. PAYE, NAPSA and NHIMA are worked out on what was earned, and each payslip goes to the worker on WhatsApp.

Hourly rate: hours clocked × the rate
Daily rate: days clocked × the rate
A shift with no clock-out pays no hours and is named before the run is released
Lateness in minutes against the shift start

A monthly timesheet PDF with a verification code

Evidence a principal can be shown.

Every clock event carries the time, the coordinates and whether it was an override. Export a monthly timesheet per worker as a PDF carrying a verification code, or as Excel, and the headcount you bill is the headcount the gate recorded.

Overrides only with a reason and a site photo; the face the camera saw is kept
An attendance map of where every clock-in happened
Short shifts recorded with a reason
The same face cannot be enrolled under two workers without a recorded override

Compared

Four ways to take a register. One that pays from it.

	Paper register	Cards or PINs	Fingerprint terminal	Xeel face attendance
Can be done for a friend	Yes — anyone can sign	Yes — cards get lent	Harder	No — face and a blink, on the spot
Hardware	A book	A reader and cards to replace	A terminal at every gate	An Android phone or tablet
Worn, dusty or wet hands	—	—	Can fail to read	Touch-free
No signal at the site	Works	Depends on the system	Depends on the system	Works, syncs later
Where it happened	No	The gate it was read at	The gate it was read at	GPS on every clock event
Into payroll	Retyped by hand	Usually an export	Usually an export	Daily and hourly pay straight from the clock

Questions

Mines and quarries, answered.

Is there a biometric attendance system for mines in Zambia that works offline?

Yes. Xeel face attendance runs on an Android phone or tablet placed at the gate or muster point. Faces are matched on the device with no network, every clock-in and clock-out is stored on the device, and the records sync when signal returns. It is used where fingerprint terminals struggle with dust and where there is no reliable network.

Can workers clock in underground?

Put the device on the surface, where workers pass on the way in and out: the gate, the lamp room or the muster point. Matching does not need signal, but the GPS fix that is recorded with each clock-in is taken on the surface, and the clock-in and clock-out bracket the shift.

How does a mining contractor prove headcount to the mine?

Every clock event is recorded with the time from the server, the coordinates and the face match, and overrides need a reason and a photo. A monthly timesheet per worker can be exported as a PDF with a verification code, or as Excel, so the heads you bill are the heads the gate recorded.

Why face recognition rather than fingerprints on a mine?

Fingerprint readers often fail on worn, cut or dusty hands and need a terminal at every gate. Face clock-in is touch-free and runs on an Android phone or tablet, with a blink check so a photo or a screen does not pass.

Does it pay hourly shift workers automatically?

Yes, for workers on an Hourly rate: the pay run multiplies the hours between their face clock-in and clock-out by their rate, then works out PAYE, NAPSA and NHIMA. Workers on a Daily rate are paid for the days they clocked in. Monthly-salaried staff are paid their salary, with attendance shown to HR.

Does it work without internet or network?

Yes. Faces are matched on the phone or tablet itself and every clock-in and clock-out is saved on the device first, then sent when signal returns, each with a key so nothing is recorded twice. The time is taken from the server's clock, so changing the time on the handset does not change the record.

What does it cost, and is there a fee per worker?

Face clock-in is part of Xeel, priced per month as one app. There is no charge per worker or per face, and the employee register is free with every plan. Message O'Sense on WhatsApp on +260 974 546 632 for current pricing.

Where is the face data kept?

The face template -- the numbers a face is turned into -- is stored encrypted on the device, with the key in the Android Keystore, and is never uploaded. Only the enrolment photo reaches the office, so a replacement phone can be set up again. How O'Sense handles biometric data under Zambia's Data Protection Act 2021 is in the privacy policy.

Known limits — not bugs. Face clock-in runs on Android phones and tablets, not iPhone. A clock-in outside a site boundary is recorded with its coordinates, not refused. Monthly-salaried staff are paid their salary, with attendance shown rather than deducted. Xeel records attendance; it does not open doors or turnstiles. The blink check stops a photo or a screen; it is not a claim that no attack can ever work.

Prove every head on the shift. Before you bill it, or pay it.