Budget, Forecast, Scenario Plan: Three Different Documents Founders Keep Merging

Most planning processes die because three documents with different jobs get squashed into one spreadsheet. Then reality diverges in month two, the file stops being updated, and the company goes back to running on instinct.

Budget: a commitment

A budget is the version of the year you are holding people to. It is set once, approved, and left alone. Its value comes entirely from being fixed: if the budget moves every month, variance analysis becomes meaningless and nobody is accountable for anything.

Properties: annual, locked, owner per line, compared against actuals monthly.

Forecast: your current best estimate

A forecast is what you now believe will happen, updated as facts arrive. It is not a target and it is not a promise. Its job is to answer "where do we land if today's trend continues" so you can act early.

Properties: rolling, updated monthly (cash weekly), unemotional, no aspiration in it.

The two coexist. Budget says we committed to £8M. Forecast says we will land at £7.2M. The gap is the conversation, and it only exists if you keep both numbers.

Scenario plan: a stress test

Scenarios ask what breaks. Not a spread of optimistic and pessimistic revenue lines, but specific shocks with specific responses:

• Ad costs rise 30% and blended acquisition cost follows
• A key supplier slips six weeks
• Your largest wholesale account leaves
• Freight rates double on the next two containers

For each, the useful output is not the profit number. It is the trigger and the action: at what point do you cut spend, reprice, or draw on a facility, and who decides.

Cadence that survives the year

• Annual: build the budget, one week, finish it, lock it.
• Monthly: close the books, update the forecast, review variance against budget with the owner of each line.
• Weekly: update the 13-week cash forecast, since cash moves faster than the P&L.
• Quarterly: re-run two or three scenarios and refresh the trigger points.

Signs your process has collapsed into one document

• The budget has been "updated" three times this year
• Nobody can state the variance to plan without opening a file
• The forecast contains a hockey stick nobody believes
• Scenarios exist as a best case and a worst case, with no actions attached

Separating them again takes an afternoon and makes every planning conversation shorter, because each question has one document that answers it.