Hello Armin,
I'll be happy to help you with this. Currently, the price does not factor in any transactional sales tax, including VAT. GitHub is responsible for remitting these taxes directly to the appropriate jurisdiction by the applicable tax laws.
If you are a business with a valid VAT number on file for your GitHub account, then the transaction is exempt from VAT and no VAT is included. Our VAT registration number is EU528001391. That is a general EU VAT number. We are registered as a single point of registration (SOR) in the Netherlands and pay out the VAT collecting jurisdictions via their portal.
Hope that clears things up, please let me know if you have any other questions.
Cheers,
Matt