3-statement-model

Use openpyxl to write Excel formula strings into cells rather than computed values, linking the Income Statement, Balance Sheet, and Cash Flow tabs. Only historical actuals and assumption drivers should be hardcoded; all projections must be formulas so the model flexes with assumptions.

Net Income flows from the IS to the top of CFO, CF ending cash becomes BS cash, and retained earnings roll forward as prior RE plus net income minus dividends. The model validates with checks: Assets minus Liabilities minus Equity equals zero and CF ending cash equals BS cash.

Yes, openpyxl writes formula strings such as ws["D15"] = "=D14*(1+Assumptions!$B$5)" directly into cells. The workbook must be recalculated after generation, for example with a recalc script, so cached values are refreshed before delivery.

Locate the filing on SEC EDGAR, identify the reporting currency and scale, then map line items from the Consolidated Statements of Operations, Balance Sheets, and Cash Flows to model rows. Extract at least three years of historicals and verify IS net income equals CF starting net income each year.

Common causes are cash not tying to the cash flow statement, retained earnings missing SBC or dividend adjustments, or working capital changes with wrong signs. Use the check rows (Assets - Liabilities - Equity = 0, cash tie-out, RE roll-forward) to isolate which linkage is broken.

Interest creates circularity through net income, cash, and debt balances. Enable iterative calculation in Excel options with 100 maximum iterations and 0.001 maximum change, or compute interest on beginning debt balances to avoid circularity entirely.