📌 Stage 2 · People and Revenue · Revenue Plan · NET 30 AR roll-forward · 40–50 min
NET 30 in practice: a 40 / 45 / 15 collection curve
Learning goals
- Explain the receivables roll-forward identity: opening + billings − collections = closing
- Model NET 30 as a three-tranche collection curve
- Read the collection-timing detail rows and the January reach-back
- Prove the year ties: collections plus the change in receivables equals billings
Concepts
The roll-forward identity
Accounts receivable is a running balance, not a monthly total. Each month the studio adds what it billed and subtracts what it collected, and what is left rolls into the next month:
=C12+C13-C14Revenue Plan C15 (January closing receivables): opening $47,025.00 + January billings $48,875.00 − January collections $57,125.00 = $38,775.00. February's opening (D12) simply links back to this cell, so the balance can never drift.
💡 Tips:
- The same identity works for cash (Lesson 14) and for the loan balance (Lesson 10) — learn it once, use it everywhere.
NET 30 as a collection curve
“NET 30” means the invoice is due 30 days after the invoice date, but real clients pay on a spread. The model approximates that spread with three tranches driven from Assumptions: 40% of billings collected in the month billed (F19), 45% in month +1 (F20), and 15% in month +2 (F21). The Best case speeds the curve to 50 / 45 / 5; the Worst case slows it to 30 / 45 / 25.
That curve is why the studio can bill $48,875.00 in January and still collect $57,125.00: part of January's money was billed in 2025.
=Assumptions!$F$19*C13Revenue Plan C17 (collected in the month billed): 40% × $48,875.00 = $19,550.00 in January.
=Assumptions!$F$20*C13Revenue Plan D18 (February, one month back): 45% × January's $48,875.00 = $21,993.75 — the formula this lesson has you retype.
=Assumptions!$F$21*Assumptions!$C$8Revenue Plan C19 (January, two months back): 15% × the $61,500.00 of November 2025 billings typed on Assumptions = $9,225.00. From March onward this row reads the sheet's own billings two columns left.
Collections are the sum of the tranches
Row 14 adds the three tranches, and that row — not billings — is what feeds the Cash Flow sheet:
=C17+C18+C19Revenue Plan C14: $19,550.00 + $28,350.00 + $9,225.00 = $57,125.00 collected in January. Column O sums to the FY figure $689,156.25.
The year must tie
Two independent facts must agree, and they do: FY billings of $690,000.00 minus FY collections of $689,156.25 leaves $843.75, which is exactly the growth in receivables ($47,868.75 closing in December minus $47,025.00 opening in January). If those two numbers ever disagree, a tranche formula or an input is wrong — this is the workbook's most useful standing check.
Practice
Fixed case: Harbor Creative Studio LLC, a four-person design studio in Austin, Texas, planning calendar year 2026. Cached numbers are the Base scenario. Pale-green cells are formulas; white cells are typed inputs. The exercise opens on the sheet this lesson teaches. Cell D18 (February collections from January billings) is blank: retype the one-month-back tranche.
- Open Revenue Plan and find the roll-forward — The exercise opens on Revenue Plan. Rows 12 to 15 are the roll-forward: opening receivables, billings (linked from row 10), collections, and closing receivables.
- Retype the February tranche in D18 — Cell D18 (collected from last month's billings) is empty. Type =Assumptions!$F$20*C13 and confirm: it should return $21,993.75 = 45% × January's $48,875.00.
- Verify the January tranches — C17 should read $19,550.00, C18 $28,350.00, C19 $9,225.00, and C14 $57,125.00. C15 (January closing receivables) should read $38,775.00.
- Check the December close — N15 (December closing receivables) should read $47,868.75, and O14 (FY collections) should read $689,156.25.
- Run the tie-out — Confirm O13 ($690,000.00) − O14 ($689,156.25) = $843.75 = N15 ($47,868.75) − C12 ($47,025.00). The roll-forward is internally consistent.
Online exercise
The spreadsheet below is editable — follow the practice steps right on this page. Steps that need ribbon menus should be done in your own Excel with the downloadable practice file.
Checklist
Work through each item; when every box passes, this lesson is done:
- ☐ Retyped =Assumptions!$F$20*C13 in D18 and it returned $21,993.75
- ☐ January closing receivables C15 reads $38,775.00 and December closing N15 reads $47,868.75
- ☐ FY collections O14 read $689,156.25 against FY billings of $690,000.00
- ☐ Ran the tie-out: billings − collections equals the change in receivables ($843.75)