Payroll app for a small team: overtime, contributions, 13th month pay

A small payroll tool takes hours worked, applies overtime and premium rules, deducts statutory contributions from configurable tables, adds 13th month pay when due, and produces a payslip and a summary for your accountant. The important design choice is that no rate or rule is hard-coded: every table is data you can edit with an effective date.

I am describing a Philippines-style setup (social security, health insurance and a housing fund, plus 13th month pay) because that is a common ask. I deliberately do not list rates or brackets here. They change, and you should take them from the agencies’ own published tables and your accountant.

What does it look like each pay period?

1. Attendance in. Hours come from a simple timesheet screen, a CSV import from a clock device, or entries a supervisor approves.
2. Pay run. You pick the period and the app creates a draft pay run for every active employee. Each line shows basic pay, overtime hours by type (ordinary day, rest day, holiday, night), allowances, and deductions.
3. Review. Click a row to see the working: which rule fired, which table row was used, and the formula. Anything unusual, such as negative net pay or hours far above the norm, is flagged.
4. Lock and publish. Once locked, the run cannot be edited without a recorded reversal. Payslips are generated as PDFs and can be emailed or downloaded.
5. Exports. A summary per contribution type and a bank-transfer file layout your bank accepts, confirmed with the bank first.

How is 13th month pay handled?

As its own calculation, not a bonus typed in by hand. The app accumulates the basic pay that counts toward it during the year, according to the rule you and your accountant agree, and shows the running balance per employee. In the pay run for the month it is due, it appears as a separate line, and partial-year and resigned employees are handled by the same rule rather than by manual adjustment.

What are the usual failure points?

• Rounding. Contribution tables and tax calculations round at specific steps. The app records the rounding rule per line so totals match what the agency expects.
• Effective dates. A table change mid-year must not rewrite past payslips.
• Mid-period changes. Raises, new hires and leavers need prorating rules you decide in advance.
• Employee classification. Which rules apply to which employee type is a setting per person, not a guess.

When is off-the-shelf better?

If you have more than a handful of staff, several branches or want direct filing, a local payroll service or established payroll software will carry compliance updates for you, and that is worth paying for. A custom tool makes sense when your pay rules are unusual (piece rates, shift patterns, mixed pay types) and the spreadsheet is where the pain is.

What I need from you

• Your current payroll spreadsheet and two or three recent real pay runs to test against, with names removed if you prefer.
• Your accountant’s confirmation of the rules and tables to load, in writing.
• A list of who should see which pay data.

I test by recalculating past periods and comparing to your known-good totals before the first live run.