How contractor invoices are generated

2 min read · Updated Jun 2026

A contract is either billed Per pay period (recurring invoices on a frequency) or Upon completion of service (a one-time invoice). For per-pay-period contracts, the compensation unit decides the amount: Monthly is a fixed set amount, while Hourly and Daily are built from approved timesheets. Recurring invoices generate automatically at the end of each period — typically overnight (around 11 PM in your time zone).

How a contractor’s invoices are produced comes down to three things you set on the Job and compensation step: the payment terms, the compensation unit, and (for recurring contracts) the invoicing frequency. See Set job details, service duration, and payment terms for where these live.

Two payment terms

  • Per pay period — invoices are generated automatically on a recurring schedule for the life of the contract.
  • Upon completion of service — a one-time, project-based arrangement; an invoice is raised when the work is done, not on a schedule.

Per pay period: the compensation unit sets the amount

For per-pay-period contracts, how the invoice amount is calculated depends on the compensation unit:

  • Monthly (fixed) — Flamingo automatically generates a recurring invoice for the agreed fixed amount each period. Nothing needs to be logged.
  • Hourly — the invoice is built from approved timesheets: hours worked × the hourly rate.
  • Daily — also built from approved timesheets: the logged hours are converted using the contract’s hours per working day, then multiplied by the daily rate.

Because Hourly and Daily invoices are based on approved time, timesheets need to be approved for those amounts to be ready — see Review and approve timesheets.

Per pay period: the frequency sets the period

The invoicing frequency controls how long each pay period is and when the invoice is generated — for example Weekly, Bi-weekly, Semi-monthly (including a 10th & 25th arrears option), or Monthly. For exactly when each frequency generates an invoice and how billing periods are defined, see How do I set a contractor’s invoicing frequency?.

What time invoices are generated

Recurring invoices aren’t created at a random moment — they’re generated at the end of the billing period, after the end of the day in your organization’s time zone (around 11 PM local time). In practice that means a new invoice usually appears overnight and is waiting for you the next morning.

The exact clock time depends on your organization’s time zone, but the rule is the same for everyone: generation happens at end-of-day, not first thing in the morning.

Upon completion of service

For completion-of-service contracts there’s no recurring generation:

  • The contractor raises a one-time invoice for the agreed amount (plus any expenses) when the work is complete.
  • When that final invoice is paid, the contract automatically moves to Completed.

Quick reference

  • Per pay period + Monthly → auto-generated each period for the fixed amount.
  • Per pay period + Hourly or Daily → auto-generated each period from approved timesheets.
  • Upon completion of service → the contractor submits a one-time invoice when done.

Note: Set the payment terms, compensation unit, and frequency when you add the contractor (and adjust them later by amending the contract). Once a contract is per-pay-period, recurring invoices are produced for you — generated end-of-day (around 11 PM your time) so they’re ready the next morning. You just review, approve, and pay.

Whatever the model, you review and pay invoices the same way — see How do I review, approve, and pay contractor invoices?. You can also let qualifying invoices skip manual review — see How does contractor invoice auto-approval work?.

Was this helpful?·

Last updated: Jun 2026

Can’t find it?

Support is here 24/7.

Contact support →