Use current tax return data to forecast next year’s liability, test different scenarios and give clients clearer answers before the next deadline arrives.
From £85 per year
Use current tax return data to forecast next year’s liability, test different scenarios and give clients clearer answers before the next deadline arrives.
From £85 per year

What If? Planner helps practices move from “here is what happened” to “here is what might happen next”, using the data already in the tax return.
Start with current SA100 data, apply next year’s rules and create a baseline view of the client’s likely liability.
Adjust income or other figures to explore outcomes without changing, submitting or interfering with the live return.
Identify where payments on account may need attention and help clients prepare for future tax bills with more confidence.
WhatIF Planner helps your practice move beyond historic tax return preparation. Use current client data to forecast liabilities, model different scenarios and give clients clearer advice before problems appear.
Use current tax return data to estimate what a client may owe next year, helping them plan earlier and with more confidence.
Forecast next year’s liability using current data
Give clients earlier visibility of what may be due
Support better budgeting conversations
Explore different income, dividend or profit scenarios quickly, without affecting the live tax return.
Test different income assumptions
Compare outcomes quickly and safely
Show clients the impact of future decisions
Identify where payments on account may be reduced based on projected liability, helping clients avoid unnecessary overpayments.
Review projected tax against current payments
Spot potential reductions earlier
Give clients clearer cash flow guidance
Flag projected increases early so clients can budget ahead, set aside reserves and avoid last-minute surprises.
Highlight changes before they become urgent
Help clients prepare for future tax bills
Reduce difficult year-end conversations
Turn complex tax planning into practical, figure-backed conversations your clients can understand.
Support advice with real calculations
Make client meetings more valuable
Build confidence in your recommendations
Move beyond preparing returns and give clients proactive advice that supports better planning throughout the year.
Create more advisory opportunities
Strengthen client relationships
Deliver more value from existing client data
The best planning moments often happen straight after a return is prepared. WhatIF Planner helps your team turn completed tax data into practical forecasts, clear scenarios and more useful client advice.
Generate a forecast for the following tax year using current return data, so clients can see what may be coming before it becomes urgent.
Forecast next year’s tax liability from current data
Apply updated tax rules to existing return information
Give clients earlier visibility of what they may owe
Explore different income, dividend and profit scenarios without changing the live tax return, helping clients understand the impact of future decisions.
Model different income and profit scenarios
Compare outcomes quickly and safely
Support advice with clear, figure-backed calculations
Compare projected liabilities with current payments on account, helping clients identify where payments may need to change.
Review projected tax against current payments
Identify potential overpayments or shortfalls
Support decisions to reduce payments on account where appropriate
What If? Planner sits inside Tax Return Production, using live SA100 data as the starting point for future calculations.
This means you can move straight from completing a return to exploring next year’s position, without rekeying data or switching tools.

What If? Planner works alongside your core tax workflow to help you move from compliance to advisory services.
Prepare accurate tax returns that form the basis for future projections and planning scenarios.
Populate dividend income quickly and accurately. Access up-to-date dividend data to complete tax returns without manual entry. It helps you ensure dividend figures are correct and consistent for the current tax year.
If you need help using the planner or interpreting projected tax results, our UK-based support team is available to provide practical guidance.

Liam McHugh, Managing Partner at Steve Pye & Co, knew his firm needed a change. With offices in Norwich and King’s Lynn, a team of 35 staff, and 2,200 clients, the firm had outgrown its previous software. One of the elements it benefited from was TaxCalc’s Charities module. Liam says: "Having previously used IRIS (for charity accounts) and then switched to Excel spreadsheets and Word documents, the module is significantly quicker than IRIS and a lot more flexible, especially when it comes to the layout and detail which can be included in the report of the trustees. It's also really easy to set up and maintain the different funds which a charity can hold."

It allows you to use current tax return data to forecast next year’s tax liability and explore different scenarios.
Yes. You can adjust or enter projected income figures to see how changes affect the final tax liability.
No. The planner is separate from the tax return and does not submit or alter the live return data.
Yes. By projecting lower future liabilities, you can identify where payments on account may be reduced.
Tax scenario planning software allows you to model different future outcomes based on a client’s current tax position. With TaxCalc’s What If? Planner, you can use existing tax return data to project next year’s liability and test how changes in income or circumstances affect the final tax bill. This helps you give clearer advice, support cashflow decisions and move beyond compliance into forward-looking planning.
Designed for accounting practices that want to give more proactive advice using data already held inside TaxCalc Tax Return Production.