Adding tax in invoices

Hi! Our plugin can only show taxes if they are charged to the customer and stored in the order in WooCommerce. As you already found out, changing the WooCommerce tax settings does not affect existing orders (which is a good thing, because you don’t want all existing orders to change when your country changes a tax rate!).
You can still ‘fix’ existing orders manually. WooCommerce locks paid orders, so to do this you’d have to change it back to an unpaid status (on-hold/payment pending), but the downside to that is that your customer will receive emails from you again. A good alternative is a small code snippet that enables editing of paid orders:

add_filter( 'wc_order_is_editable', '__return_true' );

If you haven’t worked with code snippets (actions/filters) or functions.php before, read this guide: How to use filters

You can then click the ‘recalculate’ button, which will add the tax on top of the existing prices. You will probably want to change both the price and the tax after that, to keep the total amount the same.

Hope that helps!

Hi
When i add this code my side od not working Andrzej i get error 500.. od aby other way to change the invoice ?

No, this is the only way. The snippet is fine, where did you add it? Is it possible you made a copy paste error? To be sure your browser is not copying any ‘pretty quotes’ instead of the actual quotes from the snippet, you could also try copy pasting from this link: https://pastebin.com/raw/06TvG6jW

And again: If you haven’t worked with code snippets (actions/filters) or functions.php before, read this guide: How to use filters