As of 13 August 2026, AI can only partly budget for employer payroll costs.

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 GOV.UK guidance and your payroll provider records, then collect the current employer National Insurance, pension, statutory payment, levy and other rates that apply to your budget period.
   2. Export or gather a current employee list showing headcount, salary or gross pay, pay frequency, working pattern, planned starters and leavers, and expected pay changes.
   3. Add known bonuses, overtime, commission, benefits, statutory payments, pension details, payroll fees and any other employer-paid costs, separating confirmed figures from estimates.
   4. Paste the collected information and current sourced rates into the prompt, keeping the source and applicable tax year beside each rate.
   5. Put the generated tables into a spreadsheet and test the formulas with a simple employee or group whose payroll cost you can calculate independently.
   6. Compare the monthly totals and assumptions with your payroll reports and cash plan, then ask a payroll professional or knowledgeable colleague to check uncertain treatments before using the budget for hiring or funding decisions.

   Prompt

   Build a UK employer payroll-cost budget from the information below.
   
   Business: [business name]
   Budget period: [period]
   Employees or groups:
   [For each employee or group, provide headcount, pay frequency, gross pay or salary, start date if relevant, working pattern, expected changes, bonuses, overtime, commission, benefits and termination dates if relevant.]
   
   Employer assumptions and rates:
   [Paste the current rates, thresholds, rules and payroll-provider charges you intend to use, with the source and applicable tax year or period. Include employer National Insurance, workplace pension contributions, apprenticeship levy if applicable, statutory payments, benefits in kind, payroll software or bureau fees and any other employer costs that belong in this budget.]
   
   Produce:
   1. A monthly budget by employee or group and by cost type.
   2. Monthly totals and a total for the full budget period.
   3. Separate recurring costs, one-off costs and uncertain costs.
   4. A base case, a higher-cost case and a lower-cost case, changing only assumptions I have supplied.
   5. A clear list of missing inputs, assumptions and items that may not apply.
   6. Spreadsheet-ready tables and formulas, with every formula explained in plain English.
   
   Rules:
   - Do not invent rates, thresholds, allowances, employee details or legal treatments.
   - Do not use an old rate silently. If a current source is not supplied or available, mark the item as unverified rather than estimating it.
   - Distinguish gross pay from employer on-costs and show how each total is calculated.
   - Do not decide that a worker, payment or benefit has a particular tax or payroll treatment without stating the assumption and asking me to confirm it.
   - Check the arithmetic, show intermediate calculations, and identify totals that I must compare with the payroll system or a payroll professional.
   - This is a planning budget, not a payroll submission or professional advice.

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