Formidable Pro and PayPal : How to Add Other Amount

How to collect payments from using Formidable Pro and Formidable Pro PayPal add-on.

The PayPal add-on for Formidable Pro makes is easy to collect payments from your users. You can redirect users and specific payment amount to PayPal after user submits a formidable form. But what if you want to have specific payment amounts and the option for user to write in an amount?  Doable, yes, but a bit more tricky.

Once you know the steps, though, it’s really easy.

First, add your specific amounts.

In this example, I’ve added a drop down list with specific payment options.

Formidable Pro Paypal Addon

Note the last option, Other.  When the Other option is selected, we want a previously hidden field to appear so the user can enter their own amount. We accomplish this with conditional logic.

Second, add a text field for other.

Add a Single Line Text field below the Payment Amount drop down field and label it — Other Amount.  Do not make this field required, as it will only appear if a user selects Other in Select Payment options.

Open the Field Options for the new Other Single Text Line field.

Formidable Pro Paypal

Set the Conditional Logic to: Select payment amount (or name of your Payment Drop Down List) is equal to Other.

This will cause the Other field to appear only if someone selects Other in the payment drop down option.

Great, now a user can select a predetermined payment amount or enter their own amount.  But how do we pass the correct amount to PayPayl?

Three, add a hidden field

The hidden field will calculate the total from your drop down payment options and the other amount payment option, and we will use this field to pass the correct amount to PayPal.


After adding the Hidden Field, open its Field Options and check the Calculations Calculate the default value for this field.  Then select underneath – Select a value to insert into the box below — your two Field IDs to enter their ID number in the box below.  As you can see in my example, the two field IDs are [112] and [111].  All I need to do is add a + sign between the two ID’s, making it [112]+[111].  Close the Hidden Field and save your form.

Talking to PayPal

Go to the Settings for this form, then to Payment.


Check “Send Users to Paypal after submitting this Form”, enter the text you want to appear for the charges in PayPal, and select Hidden Field for the Amount Field.

That’s it.  The Hidden field will calculate the total from your predetermined Drop Down payment options and the Other option and send correct amount to Paypal.

It may seem like a lot of steps but do it once and you’ll be set! If you run into problems, feel free to ask for help in the comments below 🙂