By Krishna Joshi, Founder, CoreStack Technology
On a construction site, attendance is money. A daily-wage crew of 40 at ₹700 a head costs ₹28,000 a day. If three names on the muster roll belong to people who were not there, that is ₹2,100 a day — more than ₹50,000 over a month of working days — paid for work nobody did. Multiply that across sites and the paper register becomes one of the most expensive documents in the business.
Geofenced attendance is the usual answer. This guide explains how it works, what radius to set, what it can and cannot prove, and what actually stops buddy punching — drawing on how we built SitePulse, our attendance app for contractors and site crews.
What buddy punching looks like on site
- A supervisor signs the roll for a friend who arrived at eleven, or did not arrive at all.
- One worker punches a card or code for another.
- A worker checks in from home, from the tea stall down the road, or from yesterday's site.
- Names that stay on the roll after the person has left the crew.
None of these needs a dishonest company. They need only a system where the record depends on one person's pen, and nobody can check it afterwards.
How geofencing works
A geofence is a virtual boundary: a point on the map and a radius around it. When a worker checks in, their phone reports its location; the server measures the distance from the site's centre and accepts the check-in only if it falls inside the radius.
In SitePulse each site has its own centre and radius in metres. A check-in from outside is refused, and the message says how far away the person is and how close they need to be — "about 45 m from the site; you need to be within 30 m". That detail matters more than it sounds. A worker told only "you are not at the site" while standing at the gate presses the button again and then gives up; a distance tells them to walk to the gate, or to call the supervisor because the fence is drawn wrong.
Choosing a radius
Phone GPS outdoors is commonly accurate to within roughly 5–20 metres, and worse beside tall buildings, under heavy cover or in a basement. A radius that is too tight refuses honest workers; one that is too wide accepts the tea stall. Sensible starting points:
| Site type | Starting radius | Why |
|---|---|---|
| Single building or small plot | 50–100 m | Covers the plot and the gate, allowing for GPS error |
| Large construction site or campus | 150–300 m, or several sites | Workers arrive at different gates |
| Dense city centre | 100–150 m | GPS drifts between tall buildings |
| Roads, pipelines and other linear works | A site per stretch, moved as work moves | One giant circle would accept anyone nearby |
Then watch the refusals in the first week. If honest people are repeatedly refused just outside a tight fence, the fence is the problem: widen it.
What a geofence proves — and what it does not
A geofence proves that a phone was inside the boundary. It does not prove whose hand the phone was in. Being honest about that is the difference between an attendance system and a false sense of security.
| Problem | Geofence alone | What closes the gap |
|---|---|---|
| Checking in from home | Stopped | — |
| Checking in at the wrong site | Stopped, if workers are assigned to sites | Site assignment |
| A friend carrying your phone | Not stopped | A check-in photo, and a supervisor who knows the crew |
| Leaving early after checking in | Not stopped by the check-in | A check-out that is measured against the fence too |
| Apps that fake GPS location | Not reliably stopped | Photo check-in, review of unusual days, and consequences |
Some vendors imply a geofence is proof of presence. It is strong evidence, and combined with the steps below it is far stronger than a signature on paper — but it is not magic, and a buyer should know that before they rely on it.
What actually stops buddy punching
No single measure is enough, so SitePulse layers them:
- Assignment to sites. A worker can check in only at a site they are assigned to, not at any site that happens to be nearby.
- A check-in photo, where a site asks for one. Each site sets photos to off, optional or required. The photo must be the worker's own and freshly taken, and one already attached to something else is refused — so yesterday's selfie does not work twice. A geofence answers "where"; a photo answers "who".
- A measured check-out. Check-out is measured against the fence as well. Inside, the day is marked present. Outside, it goes to the site manager for review, with the distance shown — "checked out 400 m away from the site" — so leaving early becomes visible.
- A person in the loop. Managers approve or reject the days that need a decision, and a rejected day is marked absent. The software flags; someone who knows the crew decides.
- One open day at a time. A worker cannot be checked in at two places at once, and a double tap on a slow connection cannot record two different outcomes for the same day.
- A register nobody types. The daily attendance register is built from the check-ins, per site, and exports to CSV or Excel for the principal employer — so there is no second, editable copy drifting away from the truth.
Field staff who are not at one site
Technicians, sales staff and supervisors who move between places need a different rule. SitePulse lets people with no site to be at record a remote day, flagged as remote on the record — unverified, but not unrecorded — rather than pretending a location check means something when there is no location to check against.
Rolling it out without a revolt
Workers are right to be wary of tracking. SitePulse records a worker's location when they check in and when they check out — it does not track them through the day. Say so clearly and early. Then:
- Start with one site and one supervisor who wants it.
- Run the paper roll alongside for two weeks and compare the two every day.
- Make sure check-in works on a cheap Android phone — SitePulse installs from a link as a web app, with no app store needed.
- Agree what happens when a phone is lost or broken, before it happens.
- Widen fences where honest people are refused; do not blame the worker for GPS.
- Turn on push notifications, so a missed check-in reaches the supervisor while it can still be fixed.
From attendance to payroll
Attendance saves money only when it feeds pay. In SitePulse, full-day and half-day rules and the minimum hours between them are set per site or globally, which turns check-ins into payable days. The Workforce Suite pairs SitePulse with CoreStack People, which runs payroll with PF, ESI and professional tax from the same attendance — built for security agencies, facility-management firms, contractors and manpower companies. It costs from ₹60 per worker per month for both, and the first ten companies in the early partner programme get three months free.
Moving the roll off paper is one example of a wider pattern; we describe the method in turning a paper register into software.
Try it on one site
Send us a list of your sites on WhatsApp or to krishan.joshi@corestacktechnology.com. We set up the geofences and show you your own sites on the map, with attendance, within a week. If your process is unusual, we will send a free design of it first.
Frequently asked questions
What is geofenced attendance?
Attendance where a check-in from a worker's phone is accepted only if the phone is inside a boundary drawn around the work site — a centre point and a radius — so presence at the site is checked rather than simply claimed.
What radius should a construction site geofence have?
Start with 50–100 metres for a single plot and 150–300 metres for a large site, allowing for phone GPS error of roughly 5–20 metres outdoors. Widen the fence if honest workers are repeatedly refused near its edge.
Does geofencing stop buddy punching?
It stops check-ins from home or from the wrong site. It does not prove who is holding the phone, so combine it with site assignment, a check-in photo, a measured check-out and a manager review of unusual days.
Can workers fake their GPS location?
Apps that fake location exist, and no location check is perfect. A required check-in photo, a check-out measured against the fence and a person reviewing unusual days make faking much harder and much more visible.
Does SitePulse track workers all day?
No. SitePulse records a worker's location when they check in and when they check out; it does not track them through the day.
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