How much cash will I have in 90 days?

Why a 90-day cash forecast changes how you run your business

Thirty days tells you if you can survive. Sixty days tells you if you can plan. Ninety days tells you if you can grow.

You want to hire a $65,000/year employee. That's roughly $5,400/month loaded. Can you afford it? Your bank account says yes. Your 30-day forecast says probably. But your 90-day forecast shows that your biggest client's contract ends in 75 days, two quarterly tax payments hit in the window, and your receivables are aging. Suddenly the answer is “not yet.”

A 90-day forecast doesn't just prevent cash crunches. It gives you the confidence to invest when the numbers actually support it, and the discipline to hold back when they don't.

What a 90-day cash forecast requires you to estimate

The same formula applies (starting cash + inflows - outflows), but at 90 days, each input carries more uncertainty:

• Month 1 inflows: high confidence. These are open invoices and confirmed recurring revenue. You can see them in your A/R aging report.
• Month 2 inflows: moderate confidence.Some open invoices, some recurring revenue you expect to continue, and maybe a few pipeline deals you're reasonably sure about.
• Month 3 inflows: lower confidence. Mostly based on historical averages and contract renewals. This is where you need to be conservative.
• Expenses across all three months.Fixed costs (payroll, rent, subscriptions) are predictable. But don't forget quarterly expenses: estimated tax payments, insurance premiums, annual software renewals, and any planned purchases.

How to build a 90-day cash forecast in QuickBooks Online (7 steps)

QuickBooks does not have a built-in quarterly cash forecast. You need to assemble data from multiple reports into a three-month spreadsheet.

1. 1
   Get your current cash balance

   Go to Reports→ search “Balance Sheet.” Run it as of today. Note “Total Bank Accounts” under Current Assets.

2. 2
   Pull receivables by aging bucket

   Go to Reports→ search “A/R Aging Summary.” Note the Current, 1-30, 31-60, and 61-90 day totals. Map each bucket to the month you expect to collect it.

3. 3
   Estimate revenue for months 2 and 3

   Go to Reports→ “Profit and Loss” and run it for the past 3-6 months. Use the average monthly revenue as your baseline for months where you don't have confirmed invoices. Subtract any known client departures.

4. 4
   Map out all expenses for the quarter

   Pull the “A/P Aging Summary” for current bills. Check Recurring Transactions(Gear icon → Recurring Transactions) for all scheduled payments. Look at the “Statement of Cash Flows” for the same quarter last year to catch periodic expenses like quarterly taxes.

5. 5
   Build a three-month spreadsheet

   Create three columns: Month 1, Month 2, Month 3. Each month has starting cash, inflows, outflows, and ending cash. Each month's ending cash becomes the next month's starting cash.

6. 6
   Create an optimistic and pessimistic version

   For the pessimistic version, reduce inflows by 20-30% and add 10% to expenses. The truth will land somewhere between the two scenarios. If even the optimistic version goes negative, act now.

7. 7
   Identify the lowest cash point

   Your ending cash in Month 3 matters, but so does the lowest point during the quarter. If cash dips dangerously in Month 2 before recovering in Month 3, you still have a problem. Check each month individually.

How to build a 90-day cash forecast in Xero (6 steps)

Xero's built-in cash flow tool only covers 7 or 30 days. For a full quarter, you need to extend the projection manually.

1. 1
   Get your 30-day baseline from Xero

   Go to Business → Short-term cash flow. Set the timeframe to 30 days and note the projected ending balance. This is your Month 1 ending cash.

2. 2
   Pull receivables data

   Go to Accounting → Reports → Aged Receivables Summary. Note the totals by aging bucket. Invoices in the 31-60 and 61-90 day columns give you a sense of Month 2 and Month 3 inflows.

3. 3
   Estimate revenue using historical P&L data

   Go to Accounting → Reports → Profit and Loss. Compare the last 3-6 months to establish an average monthly revenue. Use this as your Month 2 and Month 3 baseline, adjusting for any known changes.

4. 4
   Map quarterly and one-off expenses

   Check Accounting → Reports → Aged Payables Summaryfor current bills. Review the same quarter from last year's P&L to spot periodic expenses. Add any planned purchases or known one-off costs.

5. 5
   Build a three-month spreadsheet

   Month 1 uses Xero's projection. Months 2 and 3 are manual: starting cash + estimated inflows - estimated outflows = ending cash. Carry each ending balance forward.

6. 6
   Run scenario analysis

   Create a best-case and worst-case version. In worst-case, assume 25% of Month 2 and 3 receivables arrive late, and add a buffer for unexpected expenses. Focus on the lowest cash point across the quarter.

What it takes to maintain a rolling 90-day cash forecast

A 90-day forecast is the most useful financial tool a small business can have. It is also the most time-consuming to maintain:

• You need to update it monthly at minimum.Each month, you roll the window forward: drop Month 1 (it's now actual results), shift Month 2 to Month 1, Month 3 to Month 2, and build a new Month 3 estimate.
• Accuracy degrades over time. Month 1 is usually within 10% of actual. Month 3 can be off by 25% or more. That margin of error is fine for strategic planning, but not for precise cash management.
• The real value is in the trends. Whether your cash is growing or shrinking over 90 days matters more than the exact number. A declining trend over three months is a signal to act, even if each individual month looks survivable.

Or get your 90-day cash forecast automatically

Bottomline connects to your QuickBooks or Xero account and builds a rolling 30, 60, and 90-day cash forecast every month. It pulls actual receivables, known payables, recurring expenses, and payment history into a single projection:

The key advantage: Bottomline identifies your lowest cash point during the quarter, not just the ending balance. It also uses client payment history to give you a realistic view rather than an optimistic one. If a client has averaged 18 days late over the past 6 months, the forecast accounts for that.