Donation with request for Spanish tax receipt without TIN possible

[norbertschuler]

Describe the bug
If you choose Spain for tax receipts you need to enter a TIN in the contact form, but if you start with requesting a German tax receipt you do not need to enter a TIN. But afterwards on the screen to enter the payment data you are allowed to switch back to requesting a Spanish tax receipt without having to enter the missing TIN.

Is it on a Production or Development Build?
develop and production

To Reproduce
Steps to reproduce the behavior:

1. Make a donation requesting a German tax receipt
2. Enter a contact address without TIN
3. Change tax receipt to Spain on screen to enter payment details
4. Make the donation

Expected behavior
The donation should not be allowed for a Spanish tax receipt without a TIN.

What actually happens
The donation can be made without a TIN requesting a Spanish tax receipt.

Screenshots
Example of the form where you need to enter a TIN for your contact data requesting a Spanish tax receipt:

Example where you can modify your tax receipt at the screen entering the payment data:

Desktop (please complete the following information):

• OS: latest MacOS
• Browser: latest Chrome

[norbertschuler]

Currently the user probably just do not get a tax receipt for this donation.