Use the formula prediction method when you want to create predictions based on calculations, referenced accounts or other predictions.

Create a formula prediction

Open the forecast.
Select New prediction, then Manual prediction.
Select Formula as the prediction method.
Complete the prediction details.
Build your formula, then select Save prediction.

Build your prediction with the formula method

Before building your formula, complete the following fields:

Prediction name	Enter a meaningful name.
Account	Select the account the prediction applies to.
VAT rate override	Leave this blank to use the default VAT rate, or enter a different rate for this prediction.
Output frequency	Choose how often the prediction runs.
Output on day	Choose when to create each prediction.
Cash flow payment treatment	Choose how the prediction affects cash flow.

Build your formula

Reference accounts and predictions

Type @ to search for items you want to reference. You can reference:

Accounts
Account categories
Account groups
Other predictions

You can also use standard operators:

Addition (+)
Subtraction (-)
Multiplication (*)
Division (/)

Along with the built-in date references:

LASTMONTH
LASTYEAR
ON DATE

📌 TIP: For example, LASTYEAR * 1.1 increases last year's value by 10%.

Use conditional logic

Use the IF function to return one value when a condition is true and another when it's false.

EXAMPLE: IF(@Income>=50000,@Income*0.2,@Income*0.1)

This formula:

Returns 20% of Income when Income is £50,000 or more
Returns 10% of Income when Income is below £50,000

Use built-in functions

Formula predictions include the following functions:

SUM
AVG

After inserting a function, select the accounts and date range you want to calculate.

For example, you could calculate the average Income between January and June.

Control when a prediction runs

You can use date logic to make predictions start or stop automatically. For example, you could create a prediction that only applies to one financial year.

📌 TIP: Add a day value to the DATE() function if you need the prediction to start or end on a specific day.

Choose a cash flow payment treatment

Select how the prediction affects cash flow. Available options are:

Same day payment
Single payment
Multi: in days
Non-cash transfer

📌 TIP: For more information on non-cash transfers, check the create non-cash transfer predictions guide.

Review the results

As you build your formula, use the tabs at the bottom of the prediction builder to check the outcome.

Accounts impacted

Shows every account affected by the prediction, including:

The selected account
VAT accounts
Bank accounts
Accounts Payable or Accounts Receivable

📎 NOTE: This tab appears after you enter a prediction name, select an account and begin building the formula.

Formula values used

Shows every account or prediction referenced in your formula, helping you check that the calculation is using the expected values.

📌 TIP: Use the LASTMONTH option to reference the data from the previous month. You can then, as an example, multiply by 1.1 to add 10% to last month.

Create a 'Formula' based prediction