How do I build a forecast when the business has no trading history?

Begin with a specific operating model

State what the business will sell, to whom, at what price and through which channel. A forecast for a mobile cleaning service should reflect bookings, teams, travel and consumables. A small importer needs shipment, stock and customer collection assumptions. Starting with a target revenue total and dividing it across twelve months can conceal whether the business has the capacity or customers to achieve it.

Define the launch date and the activities required before trading can begin. Premises, equipment, licences, supplier arrangements and recruitment may each affect timing. Some requirements will be confirmed and others pending. Record those differences explicitly. If a critical approval is unresolved, test a later start rather than assuming revenue begins while the business is still unable to deliver.

Build sales from observable drivers

Choose a small number of drivers that explain revenue: jobs completed multiplied by price, units sold multiplied by selling price, or billable hours multiplied by the expected realised rate. Use the appropriate model for the service or product. Then check the operational limit. A solo operator cannot sell more hours than are available after travel, administration and other necessary work.

Support demand assumptions with actual evidence such as customer interviews, trial orders, written expressions of interest or signed contracts. These sources carry different weight. A person saying an idea sounds useful is not a purchase order, and a purchase order may still have conditions. Describe what is confirmed and what remains uncertain without converting every positive conversation into forecast revenue.

Illustrative example: a new service business

A fictional maintenance business plans to offer jobs at an average price of R2,000. The owner estimates capacity for twenty completed jobs a month after allowing for travel and administration. That gives a theoretical R40,000 monthly revenue capacity, not guaranteed sales. The launch forecast assumes eight jobs in month one, twelve in month two and sixteen in month three. All figures are invented and exclude VAT for this illustration.

Those volumes imply R16,000, R24,000 and R32,000 of revenue before considering cancellations, discounts or other adjustments. The owner records the basis for the gradual increase: current enquiries, expected conversion and available delivery days. If the only evidence is a personal target, the forecast should say so and include a lower demand case.

The cash forecast then applies the actual proposed payment terms. If some customers pay after completion and others require an approval cycle, receipts may arrive later than the work. Setup costs and consumables may be paid before the first collection. The same operating plan therefore produces both a revenue expectation and a separate funding requirement.

Use quotations and agreements for major costs

Date the evidence and note whether prices include VAT, delivery and other charges. A quote for the machine alone may omit the installation needed to make it usable. Do not fill missing costs with zero merely because a final quote has not arrived.

Separate launch spending from recurring operations

List deposits, registration costs, equipment, initial stock, website work and other setup spending in the periods when cash is needed. Then list ongoing rent, payroll, utilities, insurance, marketing and operating inputs. Some startup purchases may be assets or prepayments rather than immediate expenses, so obtain the appropriate accounting treatment while keeping the full cash requirement visible.

Include the owner’s actual funding plan and any personal cash needs that the business is expected to support. Do not hide owner withdrawals inside an unrelated operating expense. If the owner intends to contribute funds, state the amount, timing and form of the contribution and whether it is available. A hoped-for investor or unapproved loan belongs in a conditional scenario, not as certain opening cash.

Model the gap before customers pay

Working capital can be needed even when the planned activity is profitable. Stock must be purchased, employees paid and transport arranged before the customer receipt arrives. Identify those sequences for the actual business. A forecast that starts collecting revenue on the first day but delays every cost until month end may create an unrealistic picture of launch affordability.

Use the opening bank position, expected receipts and dated payments to calculate the lowest projected cash balance. Include taxes and applicable employer obligations using supported assumptions. If the model shows a funding gap, identify its amount and timing before deciding how to cover it. The funding discussion should follow the model’s actual needs rather than a round amount chosen to make the bank balance positive.

Test uncertainty without pretending to know probabilities

Prepare a base case and a slower launch case. You might reduce job volumes, delay the start or extend customer payment timing, depending on the main uncertainty. Explain why each change is plausible. Avoid attaching precise probabilities unless there is a defensible basis; a statement that a new business has a seventy percent chance of reaching a sales target can sound authoritative without supporting evidence.

Also test capacity and cost constraints when demand is stronger. More orders may require stock, staff or transport before they produce cash. An optimistic sales case that keeps every cost unchanged can be as misleading as an unsupported pessimistic case. Show the resources required to deliver the additional work and the timing of those commitments.

Keep an assumptions register that another person can follow

For each significant input, record the value, source, date, owner and reason. Mark whether it is confirmed, estimated or conditional. A reader should be able to understand why the forecast uses a particular price or launch date without relying on the founder’s memory. Retain the quotations and customer evidence behind the register.

Check that the forecast matches the written business plan. If the plan promises national delivery but the costs include only local travel, the documents describe different businesses. Government business planning guidance connects strategy, marketing, operations and finance; use that connection to test consistency. The guidance does not validate your particular sales assumptions or guarantee that funding will be approved.

Check the arithmetic and the commercial logic separately

A spreadsheet can calculate perfectly while describing an impossible operation. Check totals and formulas, then test the story behind them. If bookings increase, ask whether the same vehicle, equipment and working hours can serve them. If the model assumes a lower supplier price, identify the order quantity or agreement needed to obtain it. Do not assume a discount that has not been offered simply because a larger margin makes the plan attractive.

Run a simple zero-sales test through the early months. The result shows the commitments that continue before demand develops, such as rent, software and agreed employment costs. It does not predict failure; it makes the minimum funding exposure visible. Compare that exposure with funds genuinely available and decide which commitments can be staged before signing them.

Finally, ask someone unfamiliar with the business to explain the model back to you. If they cannot identify the launch date, main sales driver and largest cash requirement, simplify the presentation and add the missing explanation.

Replace assumptions with actual results as trading begins

After launch, compare bookings, completed work, prices, costs and collections with the forecast. Separate an incorrect assumption from a temporary timing difference. If customers take longer to approve invoices, update the cash timing. If fewer enquiries convert into sales, revisit demand and marketing assumptions. Keep the earlier forecast so the learning remains visible.

Vatco’s business budgeting and forecasting service can help organise the first model and its assumptions. Bring your proposed offering, customer evidence, supplier quotations and funding position. For the wider narrative, business plan support can help connect the financial projection with the actual operating plan. Label the result as a forecast throughout; it is a reasoned expectation, not a record of sales that have already happened.