1. A formula must not refer to other formulas

<aside> <img src="https://s3-us-west-2.amazonaws.com/secure.notion-static.com/849c8544-eedb-43d2-a146-62f0de066e5b/warning.png" alt="https://s3-us-west-2.amazonaws.com/secure.notion-static.com/849c8544-eedb-43d2-a146-62f0de066e5b/warning.png" width="40px" /> This is currently a limitation with Notion’s API, until they improve on it.
We have raised the issue with Notion.

</aside>

If you have a property that you need to refer to in the invoice, and that property is a formula, please ensure that it does not refer to another property that’s also a formula.

For example, assume you have two properties, Price and Tax, defined as follows:

| Property: Price Type: Number | Property: Tax Type: Formula Formula: prop(’Price’) * 20 / 100 | | --- | --- |

Now if you want to create another property called Total, which is formula configured as Price + Tax, then you should NOT configure it as prop(’Price’) + prop(’Tax’), because Tax is a Formula (remember, you can’t refer to another formula).

So instead, you should configure it as:

prop(’Price’) + (prop(’Price’) * 20 / 100)

If you notice that property’s value as you see it in Notion does not match its value in the invoice, then check if it’s a Formula that’s referring to another Formula.

1. Currency not showing in the invoice

<aside> <img src="https://s3-us-west-2.amazonaws.com/secure.notion-static.com/849c8544-eedb-43d2-a146-62f0de066e5b/warning.png" alt="https://s3-us-west-2.amazonaws.com/secure.notion-static.com/849c8544-eedb-43d2-a146-62f0de066e5b/warning.png" width="40px" /> Notion Invoice does not currently treat numbers as actual currency, so all totals are shown without a currency symbol.

</aside>

Instead add currency symbols in the labels on the invoice template.

More info here