A federal award. A prime contract you sit under. A joint venture where each partner carries a share. A project split across three funders with three different sets of rules. They look like different arrangements and they behave like one.
Every other runway tool assumes money lands when somebody decides to send it. Waterline assumes it lands when the paperwork says it does.
Cost share on an award. Your contribution to a joint venture. The unfunded portion of a split-funded project. Different words, one behaviour: it accrues against what you bill, it has a deadline, and it is money you have promised somebody and have to find.
Waterline schedules it on the rhythm you actually bill on, and weights it by what you billed rather than by the calendar. A month you billed nothing is a month you owe nothing.
| How you bill | When your share falls due |
|---|---|
| Monthly, as incurred | each month, weighted by what you billed |
| In arrears | at the close of each period |
| Advance | at the close — being paid early does not move the proof |
| Against milestones | per milestone, in proportion to the draw |
Your share, owed · two periods
It rises with what you bill, not with the calendar. The dashed rules are the moments somebody checks it.
The weeks between sending an invoice and the money landing are where a fully funded organization runs out of cash. Whether the payer is an agency, a prime, or a partner with their own approval chain, the arithmetic is identical. Set it once per arrangement.
A no-cost extension, a contract modification, a milestone that slips a quarter. The budget spreads thinner, your share's deadline moves with it, and payment in arrears arrives later — the half people forget.
Funds committed to one project stay committed to it. A runway figure that quietly spends restricted money to cover general payroll is worse than no figure at all.
Direct and indirect split per category, applied per period, with the part of the award you cannot spend on the work treated as what it is.
Money that arrives and leaves again. It is on your books, it is not your budget, and it should never appear in your runway as though it were.
Each funder with its own period, rhythm and share. The project is one thing; the obligations are not.
Categories, periods and rates read straight in from the workbook you already produced, and a budget that goes back out in the shape the agency expects. Nobody retypes anything, and nothing is lost in the round trip.
If you have never filed one, this section is not for you and nothing else on this page depends on it.