Since the United Kingdom leaved the EU, the EU VAT rules don't apply any more from 1st January 2021. Orders will have to go through the web shop in future and always charge the VAT of currently 20% for customers from United Kingdom.
There is an exception for Ireland. The northern part is in United Kingdom, but still applies the single market rules. So for us the whole island of Ireland is part of the European Union in relation to VAT handling.
We may still be able to write VAT free invoices to businesses (Reverse-Charge) for clients in the United Kingdom, but may need a proof from you for that. A confirmation from HM Revenue and Customs about your company's status as being VAT registered in the United Kingdom may be enough. Having a VAT ID is no longer sufficient alone.
We avoid having to register in individual foreign countries like the United Kingdom. That's one of the key benefits in VAT handling of the EU, that a registration in one country is good for 27 countries.
Clients from United Kingdom can order with old rules within 2020 to get licenses setup before changes apply.
The VAT rate in Germany changes back from 16% to 19%. If you are a person (not a VAT registered company), you can still save 3% tax if you buy in 2020. VAT registered companies reclaim VAT, so there is no benefit from a lower rate.
The country of Ireland temporarily decrease their VAT rate from 23% to 21%. The changed tax rate will be effective from September 1, 2020 until February 28, 2021. Customers in Ireland may order their licenses before 1st March 2021 to benefit from lower tax rate.
Let us know if you have questions. The whole tax scheme is subject to changes as newer laws are passed in parliaments.