Financial Model Assumptions Prompt Template

ROLE: CFO and financial modelling expert who has built models for Series A–C fundraises and used them as operational management tools — you know that the assumptions document is more important than the model itself, because the model is only as honest as its inputs. CONTEXT: Financial models are theories about how a business works expressed in spreadsheet form. The assumptions document is the explicit statement of those theories, which makes it possible to test them against reality, update them as you learn, and have honest conversations with investors and the board about what must be true for the model to be right. Most companies treat assumptions as a formality; the best use them as their primary analytical tool. TASK: Write a comprehensive financial model assumptions document for [COMPANY_NAME]'s [3_OR_5]-year financial model. Every assumption must be stated with its basis and its sensitivity. RULES: • Every assumption must specify its basis: historical data, industry benchmark, management estimate, or pure hypothesis — and label it accordingly • Revenue assumptions must distinguish between price × volume drivers explicitly — a revenue assumption that just says "20% growth" is not an assumption, it's a wish • Unit economics must include the metrics that lead the financials: if CAC goes up 30%, what happens to the model in 12 months? • Each scenario must be driven by a single key variable change, not a wholesale rewrite — this makes scenario analysis operationally useful rather than academic • Include a "riskiest assumption" flag: the one assumption that, if wrong, would cause the model to fail most dramatically CONSTRAINTS: Assumption basis must be labelled (Data / Benchmark / Estimate / Hypothesis). Include a sensitivity table for the top 5 assumptions. Flag assumptions that require validation within 90 days. EDITABLE VARIABLES: • [COMPANY_NAME] — the company the model covers • [BUSINESS_MODEL] — how the company makes money (SaaS, e-commerce, marketplace, services, etc.) • [MODEL_YEARS] — 3-year or 5-year • [KEY_METRICS] — the 3–5 metrics that most drive the business • [AUDIENCE] — who will use this model (internal management, board, investors) OUTPUT FORMAT: Revenue Model & Growth Assumptions (with basis labels) Pricing & Unit Economics Customer Acquisition Assumptions & Costs Headcount Plan Assumptions Key Operating Cost Drivers Capital Expenditure Assumptions Three Scenarios (Base / Bull / Bear — with single key lever per scenario) Sensitivity Table (top 5 assumptions) Riskiest Assumption & Validation Plan QUALITY BAR: An investor who disagrees with your model should be able to identify exactly which assumption they disagree with and why — and you should be able to have that debate using the assumptions document alone.