As of 13 August 2026, AI can only partly forecast your business cash flow.

What to actually do

1. Use a tool built for this

   The route this page recommends

2. Hand it to a person

   Second choice

   A person who owns the outcome does this end to end, worth it when the failure is dear.

3. Do it yourself

   The distant third

   A chat interface, power-user skill, and roughly 1 hour until you can act on the result.

   How to actually do it

   1. Open a spreadsheet and create columns for date or period, opening balance, customer receipts, other receipts, supplier payments, payroll, VAT and HMRC payments, loans, operating costs, other payments, net movement and closing balance.
   2. Gather current and historical bank statements, unpaid sales invoices, unpaid supplier bills, recurring costs, payroll totals, loan schedules and known VAT or other HMRC payment dates.
   3. Paste the figures into the prompt, including the opening bank balance, the date of that balance and the expected payment timing for each material receipt or payment.
   4. Ask the chatbot to produce the forecast, then copy its monthly cash-in, cash-out and closing-balance table into the spreadsheet.
   5. Recalculate each closing balance from the previous closing balance plus receipts minus payments, and compare the historical totals with the bank statements and accounting records.
   6. Mark uncertain income, late customer payments and variable costs in the spreadsheet, then ask for base, downside and upside cases that change only those marked assumptions.
   7. Compare the lowest projected balance and each HMRC, payroll, supplier and loan payment against your actual records, and ask an accountant to review the forecast before making a major financing or spending decision.

   Prompt

   Create a UK business cash-flow forecast from the data below. Use only the figures I provide and label every assumption clearly. Do not invent sales, costs, payment dates, tax amounts or opening balances. Separate actual historical figures from forecast figures.
   
   Business name: [business name]
   Forecast period: [start date] to [end date]
   Opening bank balance: [amount]
   Current bank balance and account date: [amount and date]
   Historical bank transactions: [paste or attach transactions]
   Unpaid customer invoices, with expected payment dates: [paste list]
   Recurring customer income and expected payment timing: [paste details]
   Supplier bills and other unpaid costs, with due dates: [paste list]
   Recurring operating costs and payment dates: [paste details]
   Payroll dates and total payroll cost: [paste details]
   VAT, PAYE, corporation tax or other known HMRC payments and due dates: [paste details]
   Loans, finance payments and other commitments: [paste details]
   Expected one-off income or spending: [paste details]
   Sales pipeline or other uncertain income: [paste details]
   Other assumptions: [paste details]
   
   Produce:
   1. A monthly cash-in and cash-out forecast with opening balance, net movement and closing balance.
   2. A list of every assumption, including its source and confidence level.
   3. A base case, downside case and upside case. Change only assumptions that I identify as uncertain, and show those changes explicitly.
   4. The lowest projected cash balance and the period in which it occurs.
   5. A list of payments or receipts that could materially change the result.
   6. A reconciliation showing that each historical total ties back to the supplied records.
   7. A short list of questions where the supplied data is incomplete or contradictory.
   
   Do not give tax or accounting advice. Do not present the forecast as a prediction or guarantee. State which figures I must verify against bank statements, accounting records, invoices and HMRC records. Use pounds sterling and make all calculations visible enough for me to reproduce in a spreadsheet.

   Open it prefilled in ChatGPT or Claude, or copy it into Gemini, which takes no prefill link.