Build an On-Call Pay Spreadsheet or Use a Tool?

Every engineering team that runs on call rotations eventually faces the same question: build something in-house or use a dedicated tool? For on call pay, both are viable — depending on your team size, incident volume, and how much time you want to spend on a non-core process each month. This guide gives you an honest assessment of each.

Building your own on call pay spreadsheet

For a small team with a simple policy, a spreadsheet is entirely workable. Here is what a functional one looks like.

What you need

• A list of on call dates per engineer for the reporting period (from PagerDuty or manual entry)
• A column that classifies each date as weekday, weekend, or bank holiday
• Separate rate cells for each day type — easy to update when rates change
• A column for incident count (callout fees)
• A column for incident work hours (if your policy includes an hourly rate)
• A summary row multiplying days × rate + incidents × fee + hours × hourly rate

A simple Excel formula structure

The core of a DIY on call pay spreadsheet is a day-classification lookup. With a list of bank holiday dates on a separate tab, you can classify each date like this:

Then use SUMIF to total each category and multiply by its rate. This works well for a handful of engineers with straightforward policies.

Where spreadsheets start to break down

• Manual data entry — someone has to copy on call dates and incident counts from PagerDuty into the spreadsheet every month. This takes time and introduces transcription errors.
• Bank holiday maintenance — you need to keep the bank holiday date list up to date, using the right regional calendar. This is easy to forget until it produces a wrong figure.
• Time zones — if you have engineers in different time zones, the spreadsheet does not handle this automatically. A day that is a bank holiday in GMT+0 is still a Sunday in a different time zone.
• Policy changes — when rates change, you have to update every formula or cell reference carefully. A missed cell compounds silently.
• Multiple engineers — a sheet that works for three engineers becomes unwieldy at fifteen, particularly when each has different on call patterns.
• Audit trail — spreadsheets are hard to audit. If a pay figure is questioned three months later, you need the version of the spreadsheet from that month and confidence that it was not modified after submission.

When a dedicated tool is worth it

A tool becomes worth it when the ongoing maintenance cost of your spreadsheet exceeds the subscription cost — and that crossover happens earlier than most teams expect.

1. 1You have more than 4–5 engineers on the rota. At this scale, the data entry alone takes a meaningful slice of someone's time each month.
2. 2Your policy has complexity: minimum-hours rules, business hours exclusions, tiered rates, multiple regions. Each complexity multiplies the chance of a spreadsheet error.
3. 3You have had a payroll error due to an incorrect pay report. One underpayment complaint is usually enough to justify a more reliable process.
4. 4The person who built the spreadsheet has left or moved to a different role. Inherited spreadsheets with undocumented formulas are a significant operational risk.
5. 5Finance is asking for a more consistent format. If your report looks different every month, payroll cannot process it efficiently.

What to look for in a tool

If you decide a tool is the right call, here is what matters:

• Direct PagerDuty API integration — the tool should pull on call intervals and incidents directly, not require manual export/import
• Regional bank holiday handling — especially important for UK teams covering multiple nations
• Configurable rates — weekday, weekend, bank holiday stipends; callout fee; hourly rate; minimum hours
• Finance-ready output — a properly formatted XLSX that payroll can accept without reformatting
• Per-engineer breakdown — individual line items, not just a total, so engineers can verify their own figures
• Consistent format — the same structure every month, so finance can process it without re-learning

The honest answer

If you have a team of two or three engineers, a simple policy, and time to maintain a spreadsheet, start with the spreadsheet. It costs nothing and gives you a good understanding of what the numbers represent.

If you have more than five engineers, a policy with multiple components, or if the spreadsheet is already causing pain — a dedicated tool pays for itself quickly in time saved and errors avoided. The monthly on call pay report should take minutes, not hours.