Flow Screen currency formula - how to return null value?

Question

I have a screen flow with a Currency screen element.

I'm trying to set the default value with a formula. The formula will either have a value, or it won't.

If the result of the formula is null, the flow errors when I reach that page.

It looks like the result of the formula must be a non null value.

The formula I want to use:

IF(
  CONDITION, null,
  {!MyVar.My_Currency_Field__c}
)

The formula I have to use:

IF(
  CONDITION, 0,
  BLANKVALUE({!MyVar.My_Currency_Field__c}, 0)
)

Notice how I'm being forced to provide a value, in this case 0.

NOTE: this happens regardless of whether the currency field is required or not.

Is there a way to return a null value in a Currency flow formula?

This same behaviour doesn't seem to happen with a Number field, so it seems something specific to the Currency field.

Answer 1

I tried some simple tests in a sandbox. I created a simple Flow:

I made my Currency Flow Formula just be the value of a currency field on the object:

Then I set up my screen element like yours:

• When the field on the object had a value - even zero - the Flow ran & the value showed in the screen element.
• When the field on the object had no value, the Flow errored with a GACK like yours.

---

I created a new Number Flow Formula - just like the previous one, but Number instead of Currency:

I changed the Screen element to use the new formula instead.

The Flow ran the same for values in the object field. But this time when the object field had no value, the Flow ran and displayed an empty field in the Screen element:

---

A couple of different tests:

• I made the Screen field be a Number field but used the Currency Formula...

  

...and it did NOT error on a null field value.

Which tells me that a Currency Flow Formula can return a null value which can be used elsewhere in the Flow.

• I also skipped the Formula and made the Screen Currency field look like this...

  

...and it also handled a null object field just fine directly.

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So although I could find nothing definitive in my searches, it seems that a Flow Screen Currency Field cannot handle a null formula, even though it can handle a null field directly.

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The workarounds seem to be:

• Change your Flow Formula to Number type and just use it in your Currency field Screen.
• Add a Decision element to check your Currency Formula for a null value, then have two different Screen elements to display depending on the Decision: one that uses the Currency Flow Formula, and one that does not.