Billable expenses and markup
Costs incurred for a customer, passed through at cost or with a markup, and never billed twice.
Any expense, bill line or item receipt can be marked billable to a customer or project.
Markup is set as a percentage or a fixed amount, per line or by a default rule for that customer. Billing at cost is a choice you make, not the only option.
The unbilled queue (Reports → Unbilled costs) lists every billable cost not yet invoiced, by customer and project. This is one of the most reliable sources of found money in a small business: work that was done, paid for, and never charged on.
Billed once, and only once. When a cost reaches an invoice it is marked billed and drops out of the queue. Removing it from the invoice puts it back.
The Bookkeeping Command Center raises a work item when billable costs sit unbilled beyond your threshold, so the queue does not need remembering.