Service call register format: track engineers and open calls

Service and rental. By Aman Dobriyal. Updated 2026-10-12.

A service call register format is only useful if it can answer one question at any moment: which calls are still open, and who has them? Most registers record that a call came in. Very few record that it was closed.

This one records both. It works in a ruled book or in Excel, and I'll say plainly where each one gives up.

The service call register format, column by column

Call number.
Date and time logged, and who took the call.
Customer, site and phone.
Machine: model and serial number.
The problem, as the customer reported it.
Covered by contract, under warranty, or chargeable.
Engineer assigned, and when.
Status: open, assigned, waiting for part, closed.
Date and time closed.
Work done and parts used.
Amount collected, if any.
Service report number, signed by the customer.

Four rules for the register

Before logging a call, check whether that machine already has one open. Duplicates hide how many real calls you have.
A call is closed when the engineer's report reaches the office, not when he says so on the phone.
Every morning, read the open calls oldest first. Anything open longer than you allow gets a phone call to the customer from the office, before the customer phones you.
Waiting for part is a status, not an excuse. Write which part and the date it was ordered.

The report the engineer fills on site

The register is the office's view. The service report is the proof. Use a duplicate book: one copy for the customer, one for the office.

Call number, so the report can be matched to the register
Time he arrived and time he left
Fault found and work done
Parts used, with quantities
The meter reading, if it is a rental machine
Payment taken
Customer's name and signature

The same register in Excel

One row per call, with the columns above.
Filter Status to hide closed calls. What is left is today's work.
Add Days open: =TODAY() minus the date logged. Sort by it, largest first.
A pivot table by engineer shows how many open calls each one is carrying.
Once a month, sort by serial number. A machine with many calls is telling you something about the machine, the customer or the last repair.

Where the book and Excel break

Engineers report by phone in the evening and the office types it up the next day. The register is always yesterday.
Paper reports come back in a bundle at the end of the week, so calls stay open on paper long after the work is done.
When a customer rings to ask where his call stands, nobody can say without phoning the engineer.
Attendance and travel claims live in a different register, and nobody checks them against the calls.

With two or three engineers and a careful coordinator, the book holds. It stops holding when the coordinator spends the day on the phone asking engineers what they have done.

What software changes

In the field service system I build, every complaint becomes a call with a number, an engineer and a clock on it. A new call warns you if that customer already has one open. Engineers see their calls on the phone, fill the report with parts used, payment taken and a photo, and close the job there. Calls open too long show in red for the office and for the engineer, with a reminder in the morning. Every visit lands on the machine's own log book, and attendance is an odometer photo at the start and end of the day.

What it doesn't do: send an engineer to a call he is avoiding. It makes it impossible not to know. It also needs mobile data on site, because there is no offline mode today.

Short answers

What should a service call register contain?

A call number, when it was logged and by whom, the customer and site, the machine's model and serial number, the reported problem, whether it is under contract or chargeable, the engineer assigned, the status, when it was closed, the work done and parts used, and the service report number.

When is a service call closed?

When the engineer's service report is with the office, showing the work done, the parts used and the customer's signature. A phone call saying it is done is not a closure.

How do I see overdue service calls in Excel?

Add a days-open column using =TODAY() minus the date logged, filter out closed calls, and sort by days open with the largest first. Use conditional formatting to colour anything past your limit.

Service calls with overdue tracking are one half of my field service and rental billing product. The other half is meter billing. If your coordinator spends the day chasing engineers by phone, see how it works, or leave your number and I'll call you back. Field service and rental billing. Leave your number for a call back.