The 13-Week Cash Forecast: One Audited Anchor, Everything Else Labeled

Most FP&A tools handle monthly cash reasonably well and treat weekly cash as an afterthought: a manual spreadsheet a treasury analyst rebuilds every Monday from whatever numbers didn’t move too much since last week. That gap is exactly where covenant surprises and liquidity scrambles come from: the monthly plan says you’re fine, and the actual week you run short of cash slips through because nobody was watching at that resolution. Rexfin’s 13-week view exists to close that gap without inventing numbers to fill it.

Built on the plan you already have, not a new one

The 13-week forecast doesn’t ask you to build a separate weekly model. It derives weekly cash from the monthly series already in your rolling plan, split into a direct-method view: customer receipts, supplier payments, operating expenses, tax, plus investing, financing, and FX lines kept distinct. Anything left over that the direct-method split can’t cleanly attribute shows up as a visible “other operating (residual)” line rather than getting absorbed silently: the derivation can’t quietly invent or destroy cash to make the math look tidy.

Turning a monthly number into thirteen weekly ones requires an assumption, and Rexfin states it instead of hiding it: cash is spread evenly across the days in each month, then allocated to weeks so that a month’s four-or-so weeks sum back to that month’s total exactly, down to the cent. That’s the one modeling choice underneath the whole view, and it’s labeled on the page, not left for someone to discover the hard way when the numbers don’t add up the way they expected.

One number is audited. The rest says so.

Only one figure in the entire view carries an audit citation: the opening cash balance, pulled from the anchor filing’s cited cash position at the prior year-end. That cell drills to the provenance drawer like any other cited figure, re-hashed against the source page. Everything downstream of that anchor (every week’s receipts, payments, and closing balance) is plan-derived and marked as such throughout, never blended into the view as if it carried the same weight as the one number that’s actually audited.

That distinction matters more than it sounds. A 13-week cash view that quietly presents plan output with the same visual confidence as an audited actual is the kind of thing that looks fine until a lender or board member asks which number is real. Here, the answer is always visible, not buried in a footnote.

What you can flex, and what you can’t invent

Timing assumptions (days sales outstanding, days payable outstanding, days inventory outstanding) are adjustable through what-if sliders, and the shift runs through the same deterministic engine that drives the rest of what-if modeling: push receipts out by a week and the weekly math still ties exactly, no rounding drift, no silent recalculation gap. If a shift pushes cash flows earlier than day one or later than week thirteen, the view says so by name rather than dropping the flow silently: you see exactly what left the window and why.

Minimum-liquidity thresholds work the same way: you name a level, the view flags the first week that breaches it, and nothing about that threshold is a built-in default pretending to be policy. If you haven’t set one, there isn’t a phantom line implying you have.

Where it shows up, and where it deliberately doesn’t

The 13-week sheet is available in the exportable workbook as a clearly advisory tab, present even when the underlying data can’t fully support it, in which case it states the reason rather than showing a blank. It is deliberately absent from the board pack export: board packs stay built on audited and modeled figures with proper citation weight, and mixing in a plan-derived weekly cash view there would blur exactly the audited/unaudited line this whole feature is designed to keep sharp.

Who needs this

Treasury teams managing covenant headroom week to week, not just month to month. CFOs who’ve been burned once by a monthly cash plan that looked comfortable right up until a specific week wasn’t. Anyone who wants weekly liquidity visibility without spending Monday mornings rebuilding a spreadsheet that was already stale by Wednesday.

To see the 13-week view running against a real filing, book a demo. For the rest of the forecasting and modeling tour, start at the pillar hub.