A quarterly what-if set is four standing scenarios a finance team re-runs on its rolling cash flow forecast every quarter, whether or not a decision is on the table: losing a key customer, a price rise, a foreign exchange move and a book-wide delay in customer receipts. Each one produces a single output, the number of weeks of headroom before the forecast crosses your cash floor, and the point of running them every quarter is to watch that number move.
No professional body prescribes this set or the quarterly cadence. It is a practical default, and it works because a rolling 13-week forecast is itself a quarterly instrument: a quarter of settled invoices to re-measure payment behaviour against, a quarter of exchange-rate movement, a VAT return cycle. This guide gives the method and the output for each of the four.
Standing tests are not the same as decision scenarios
Our scenario planning guide covers the three cases every finance team should maintain: a base, a downside and an upside, reviewed weekly. Our guide to cash flow scenarios for big decisions covers the temporary ones: a hire, a large purchase, your largest customer paying late, each built when the decision arises and merged or retired when it is made.
The quarterly set sits between the two. The four scenarios here are shocks the business does not choose and cannot schedule, so they are worth testing on a fixed rhythm rather than waiting for the week they happen. They are single-shock tests: each one changes one thing and holds everything else fixed, so the result is readable. Combining them into a coherent bad quarter is the downside case's job, and it stays with the standing three.
One rule governs all four. The output is expressed as headroom in weeks, with the breach week named alongside it. Guidance from the accounting bodies points the same way: ICAEW's liquidity guidance asks for the lowest point of headroom on a 13-week view, and the FRC's going-concern guidance for larger companies describes stress testing as a way to find the week a facility runs out or a covenant is breached. Headroom is the number that compares from one quarter to the next, which is what a standing test needs. The minimum balance tells you how bad; headroom tells you how soon.
How to run the quarterly set
Step 1: Refresh the base and confirm the floor. Start from the current 13-week forecast with the latest actuals recorded, and confirm the minimum usable cash balance the business must not cross. Every scenario below is measured against that line, so if the floor has moved since last quarter, change it first and note why.
Step 2: Gather the four input sets. Each scenario needs inputs the team already holds: the contract terms and direct costs for your largest customers; the effective dates, invoicing cycle and payment terms for any price change; a list of open foreign-currency items and their settlement weeks; and the paid-versus-due history for every customer with a material balance.
Step 3: Build each scenario as its own layer on the base. Copy the base, change only what that shock changes, and leave payroll, rent, tax, facility repayments and every other customer untouched. A scenario that quietly assumes a cost cut is a plan, not a test. Keep last quarter's layers so this quarter's can be compared with them.
Step 4: Read each result as headroom in weeks. For each layer, find the first week closing cash crosses the floor and count the weeks between now and then. If no layer breaches inside 13 weeks, record the lowest headroom in the window instead and, where a contract's run-off extends beyond the horizon, extend that one scenario on the monthly view.
Step 5: Record the four numbers and compare them with last quarter. Four headroom figures, four breach weeks, and for each a note of the lever that would extend it and how long that lever takes to act. Then diarise the next run, and re-run any single scenario early if its trigger moves: a customer gives notice, a supplier writes about prices, a large foreign-currency contract is signed, or collections start to drift.
Scenario one: losing a key customer
The shock is a date, not a percentage. Three of the four inputs come from the contract rather than the ledger: the notice period, the final invoice date and its payment terms, and the direct costs that stop when the customer does. Receipts do not stop on the notice date. Work delivered up to termination is still billable, and the final invoice is collected on the customer's normal terms, so the last receipt lands a full terms cycle after the last delivery. Work in progress at the notice date is a receivable the business has not yet raised, and it is cash if it can be billed and is not disputed.
Run the scenario in two stages. First, the unmitigated loss: copy the base, zero that customer's receipts from the last-receipt date forward, remove the directly attributable costs from their own stop dates (subcontractors, licences, freight, commissions that cease), and leave the fixed cost base exactly where it is. Salaried staff do not stop unless a decision is taken, and that decision carries its own cash cost. Second, if the first stage breaches the floor, layer in the cost actions one at a time from the earliest week each one changes cash, not the week it is decided.
The output is the number of weeks between the last receipt and the first floor breach, plus a named list of the cost lines that are levers and how many weeks of notice each carries. The second half matters more than the first. A business with eight weeks of headroom and two levers that each take twelve weeks to act is in a worse position than one with six weeks and a lever it can pull on Friday.
On which customers count as key: no professional body sets a revenue share at which a customer becomes a cash risk for a business of this size. The 10% figure in circulation is a disclosure rule from segment reporting standards for listed companies, which requires them to say when one customer accounts for a tenth of revenue; it says nothing about cash and does not apply to a private business. Define a key customer operationally instead: any customer whose loss, modelled as above, moves the breach week. Run the test for each of them.
Scenario two: a price rise
Two directions, and they are different scenarios rather than one with the sign flipped.
When the business raises its own prices, the cash effect lags the decision by the full length of the invoicing and collection chain. New prices apply to invoices raised after the effective date, not to work already invoiced, and those invoices are then collected on the customer's terms. A rise effective on 1 October, invoiced monthly in arrears with 45-day terms, first reaches the bank in the second half of December. Where prices are set by contract and need notice or renegotiation, add that period at the front. On the forecast, leave the receipt profile alone until the first post-effective-date invoice would be paid, then step the receipt lines up by the rise from the week the money lands.
Volume loss is the assumption that decides whether the rise is cash-positive at all, and there is no reliable figure to borrow. The academic evidence on customer response to business-to-business price rises shows it depends on the size of the increase, the customer's tenure and how the change is communicated, and none of the populations studied looks like an 11–50-person business. Set the assumption yourself, from your own renewal and cancellation history, then run it twice: the case you expect and a worse one. The useful output is the break-even, the level of customer loss at which the price rise stops improving cash. That is the number to watch against, quarter by quarter, as the real response arrives.
When a supplier raises theirs, the same lag logic applies on the payables side and the cycle is usually shorter, because supplier terms tend to be tighter than customer terms and the effective date is not yours to set. The output here is the incremental cash cost by quarter and whether it breaches the floor. If the plan is to pass the increase on, model that as a second layer rather than netting it silently into the first; a business that raises prices and absorbs a supplier rise in the same quarter is cash-negative for at least one terms cycle before it is cash-positive, even when the two rises match in percentage terms.
For UK readers there is a tax line to carry. VAT returns are usually quarterly and the return and payment fall due one calendar month and seven days after the period ends. On standard VAT accounting the tax point is the invoice, not the receipt, so higher prices mean higher output VAT falling due on the next return whether or not the customer has paid. The Cash Accounting Scheme, which ties VAT to receipts, is only open to businesses with taxable turnover of £1.35 million or less, and a business must leave it above £1.6 million, so at £2.5 million and up the invoice basis is a given. Price the VAT outflow into the scenario a quarter ahead of the receipt.
The environment is not neutral on this. In May, 44% of UK businesses with 10 or more employees told the Office for National Statistics they would respond to rising employment costs by increasing prices. If that includes your suppliers, the second half of this scenario is coming whether you run it or not.
Scenario three: an FX move
At this size the exposure is usually transactional: a receivable or payable in a currency you do not report in, or a foreign-currency bank account. A subsidiary in another currency is a reporting question, not a 13-week cash question, and it belongs in the consolidated view rather than here.
The arithmetic is deliberately simple. List every foreign-currency item still to settle inside the horizon, in its own currency, with its expected settlement week, and add the balance of any foreign-currency account you will convert or spend against sterling costs. Net the list by currency and by week: a US dollar receivable settling in week four and a dollar payable in week five largely cancel, and the exposure is the net, not the gross. Skipping the netting overstates the risk. Exclude anything already fixed by a forward contract. Then apply the move to the net exposure at each settlement date and re-read the closing balance line against the floor.
Compute the sterling value exactly rather than applying a flat percentage, because the answer depends on which way the rate is quoted. A $100,000 receivable modelled at 1.25 dollars to the pound is worth £80,000. If sterling strengthens 5% to 1.3125, the receipt becomes £76,190, a swing of £3,810. If sterling weakens 5% to 1.1875, it becomes £84,211, a gain of £4,211. For a payable, the signs reverse. Run both directions, because a favourable move on receivables is an unfavourable one on payables.
How large a move to test is a scenario choice, not a standard, and the history says 5% is not a tail event. On Federal Reserve monthly averages, sterling fell from 1.232 to 1.132 against the dollar between June and September 2022, about 8% in a quarter, and from 1.420 to 1.314 between June and September 2016, about 7%. Moves of that size inside a quarter have also occurred in the euro, Australian dollar and New Zealand dollar pairs. Test plus and minus 5% as the standing case and plus and minus 10% as the stress, and widen the band for any pair that has moved more than that in the last year. Any rate you use as the base should be written down with its source and date, so next quarter's test starts from the same place.
The output is the cash swing on the net open exposure at each band, in home currency, and whether either direction crosses the floor in any week. For most businesses of this size the answer is a swing rather than a breach, and the value is knowing its size a quarter early.
Scenario four: a delayed receivable, across the whole book
This is not the decision scenario in which your largest customer pays one invoice six weeks late; that case, and the government research on late payment behind it, is in our guide to cash flow scenarios for big decisions. The quarterly version is a re-measurement of the whole receivables book, and it has two halves.
First, refresh the observed gap. For each customer with a material balance, take the settled invoices from the last quarter and measure the days between the contractual due date and the actual paid date. Use paid-minus-due rather than paid-minus-invoiced, because the second measure mixes the customer's behaviour with your own terms. Use the median where there are enough invoices to make one, and a reviewed expected date where there are not. Company-level DSO is a fair trend indicator, but it blends sales mix, terms and collections into one number and is too blunt to shift receipts customer by customer.
Second, slide and stress. Take the open ledger and move each expected receipt by that customer's observed gap. Invoices already past due are placed from today, not from the due date, or the scenario puts cash in the past. Then run it again at the observed gap plus a stress margin, and keep widening the margin until the forecast first breaches the floor. The margin you reach is the output: the number of weeks of collections slippage across the book that the business can absorb. Refresh it every quarter and compare it with the last, because the trend in the tolerance tells you more than its level.
There is no external benchmark for how far collections drift quarter to quarter at this business size, and your own ledger is the only reliable source for the input. What there is, in some markets, is a public reference for the stress margin. Australia's Payment Times Reporting Scheme publishes how long each large business takes to pay its small suppliers, including its slowest payments, so an Australian reader can look a large customer up and use its published slow-payment figure as the stressed gap. UK readers can check whether a large customer holds a Fair Payment Code award and what it committed to. New Zealand repealed its equivalent register in 2024, and the US has no register for private-sector payment behaviour, so readers there work from the ledger alone.
UK readers should also know the terms themselves may change. The Commercial Payments Bill before Parliament would cap business-to-business payment terms at 60 days and make interest on late payment mandatory at 8% above the Bank of England base rate. It is not yet law and is not expected to be in force before 2027, so the current contractual terms govern this quarter's test.
Reading the four together
Each scenario produces one line for the board: headroom in weeks, the breach week, and the lever. Four lines, refreshed quarterly, and the change in each from last quarter is usually the conversation worth having.
Two things the set does not do. It does not combine the shocks; a quarter in which a customer leaves, a supplier raises prices and collections slow all at once is the downside case, built as a coherent story in the standing three. And it is not exhaustive. A supplier failing rather than repricing, an energy or employment cost rise with no terms cycle to soften it, and a facility being withdrawn are all shocks a finance team might add. Four with a method each is a better starting point than eight with none.
How Float fits
Float connects to Xero and QuickBooks Online, with a Sage Intacct connection in development and a waitlist open, imports reconciled bank balances, invoices and bills every day with a manual refresh on demand, and keeps a rolling 13-week and monthly forecast current. The base each quarterly scenario is copied from is therefore live, not last month's export.
Scenarios in Float are layers. Each one is created and named, its budgets stack on top of the base forecast, and the graph shows the base line and the scenario line together. Several layers can be compared on one view, and when a decision is made its budgets move into the base. A layer can also be duplicated as the starting point for a new one, which is how last quarter's four become this quarter's four. Every plan includes a set allowance of scenario layers, listed on our pricing page, with more available at additional cost.
The four scenarios map onto ordinary budget mechanics. The price rise runs on a repeating budget that steps up or down each occurrence by a fixed amount or a percentage. The key customer and delayed receivable scenarios run on re-dated or excluded budget occurrences and on expected payment dates set against invoices and bills, none of which writes back to the accounting records. For the FX scenario, Float converts foreign-currency accounts, invoices and bills into your base currency for display and shows the rate used on each item, so the open-exposure list starts from figures already in the forecast; the move itself is entered as a scenario budget for the difference at each settlement date.
Reading the result is what the cash floor is for. Set a threshold and Float shows the date the balance is due to cross it, so comparing four scenarios is a matter of comparing four dates. The scenario comparison graph in Insights layers them on one chart in days, weeks or months and exports to PNG for the board pack. Admin, Editor and Viewer roles keep the layers editable by the finance team and visible to leadership.
Frequently asked questions
What is a quarterly what-if set?
A quarterly what-if set is a fixed group of cash flow scenarios a finance team re-runs on its rolling forecast every quarter, whether or not a decision is pending. The four in this guide are losing a key customer, a price rise, a foreign exchange move and a book-wide delay in receipts. Each produces the same output, headroom in weeks before the cash floor is crossed, so the four numbers can be compared with last quarter's.
How often should a finance team run cash flow scenarios?
Maintain the base, downside and upside cases weekly, run the standing what-if set quarterly, and build a decision scenario whenever a specific choice arises. No professional body prescribes the quarterly cadence; it is a practical default that matches the 13-week forecast horizon and the natural refresh cycle of the inputs. Re-run any single scenario early when its trigger moves, such as a customer giving notice or collections drifting.
How do I model losing a major customer in a cash flow forecast?
Copy the base, zero that customer's receipts from the date the last invoice would be paid on normal terms, remove only the direct costs that stop when they do, and leave the fixed cost base unchanged. Read the first week the forecast crosses your cash floor and count the weeks of headroom. Then layer in cost actions one at a time from the week each one actually changes cash, and record which levers extend the headroom and by how much.
What percentage of revenue makes a customer a concentration risk?
No professional body or independent study sets a revenue share at which a customer becomes a cash-management risk for an 11–50-person business. The 10% figure often quoted is a disclosure threshold from segment reporting standards for listed companies, not a risk threshold. Define a key customer as one whose modelled loss moves your breach week, and test each of them.
How do I forecast the cash effect of a price increase?
Apply the new price only to invoices raised after the effective date, then move the cash effect to the expected collection date, which is the invoice date plus terms plus any observed delay. Set an assumption for volume or customer loss from your own history and run it at two levels. The useful output is the break-even level of customer loss at which the rise stops improving cash. In the UK, also add the higher output VAT falling due on the next quarterly return, which lands before most customers have paid.
How do I model an exchange rate move on a cash flow forecast?
List every foreign-currency receivable, payable and account balance still to settle inside the horizon, net them by currency and settlement week, and exclude anything fixed by a forward contract. Reconvert the net exposure at the stressed rate for each settlement date, computing the home-currency value exactly rather than applying a flat percentage, and read the closing balance against your floor. Test plus and minus 5% as the standing case and 10% as the stress, and record the base rate, its source and its date.
How much should I stress collections in a cash flow forecast?
Start from each customer's observed payment gap, measured as actual paid date minus contractual due date over the last quarter, and slide expected receipts by that amount. Then add a stress margin and widen it until the forecast first breaches the floor. The margin you reach is your collections tolerance in weeks. There is no external benchmark for how far collections drift quarter to quarter at this size, so the ledger is the input and the trend in the tolerance is the signal.
Who can see or change the scenarios in Float?
Float uses three roles. Admins have full control, Editors can build and change forecasts and scenarios, and Viewers have read-only access, so a scenario carrying sensitive assumptions such as a planned price rise can be visible to leadership without being editable outside the finance team. The connection to your accounting platform is one-way: Float reads from Xero or QuickBooks Online and never writes back.
The value of a standing test is the quarter it buys you between seeing a consequence in the forecast and meeting it in the bank account. Start a free 14-day trial of Float and run this quarter's four scenarios as layers on a live forecast of your own numbers.
