I calculate in excel lead to logic blocks

[Rogerio_Rios (Professional Support)]

@dora_paz

VAT number

I unmarked my solution: you have the aia and the blocks.

A suggestion: as the algorithm is based on calculations only, use a java example and use the tool to create an extension. Is not difficult.
https://www.google.com/search?client=firefox-b-d&q=vat+number+validate+algorithm+java

If this is not correct, just look on Google…

[Still-learning (1-2-3-4...)]

Yes extension would be good. Also they can try with some free api also

https://www.isvat.eu/

[dora_paz (Dora)]

@Still-learning link provided is for EU countries only. Also this was just to show that many things can be done without extensions or use of an api.

[Chsytem]

I really appreciate your time and response and kindness on my topic, you helped me a lot to orient myself and to continue. I thank you again.