Customer billing

Three patterns for billing a customer for project work:

Pattern	When
Fixed price	The customer agreed a total at the start
Time-and-materials (T&M)	Bill the hours logged, at agreed rates
Milestones	Bill on agreed deliverables (e.g. 30% on kick-off, 40% on first milestone, 30% on delivery)

Fixed price

Simplest:

Sale order to the customer for the agreed total
Project is created linked to the sale order
Invoice the full amount when work completes (or at kick-off, or per your payment terms)

Hours logged are tracked for internal profitability but don't drive invoicing.

Most common for consulting and custom development:

Sale order to the customer with service products representing "Hours" (e.g. "Junior Developer hour" at BGN 60, "Senior Developer hour" at BGN 100)
Project created linked to the sale order
Team members log timesheets against project tasks
At month-end, invoice the customer for the logged hours at their billing rate

PLANA generates the invoice from the timesheets:

Sale order → Invoice → invoice lines are pre-filled with the billable hours.

The customer's invoice shows time per developer, per day or per task (configurable).

For larger projects:

Sale order with milestone products:
- "Project kick-off — 30%" — BGN 30,000
- "Phase 1 delivery — 40%" — BGN 40,000
- "Final acceptance — 30%" — BGN 30,000
Invoice each line as the corresponding milestone completes
Customer pays per the invoice's payment terms

Track milestone completion in the project's tasks (mark the relevant task done → invoice the milestone).

For T&M with a cap:

Honest communication beats surprise invoices.

Before invoicing, glance at the Project profitability report:

Metric	Where
Revenue invoiced	Sum of confirmed invoices linked to the project
Revenue to invoice	Time logged but not yet billed
Cost	Sum of timesheets × hourly cost + direct expenses
Margin	Revenue – Cost

A negative margin warns you to investigate scope creep or under-pricing before the next milestone.