Should I send stock to Germany before my VAT number arrives?

You don't have to wait for the number. Import VAT on goods your company imports for its business from its declared start of activity in Germany can be deducted as input VAT even before the tax number is issued. Three things matter: your company owns the goods when they are imported, the import is declared for your company (for a company outside the EU, the freight forwarder declares as indirect representative), and you receive the import VAT notice (Einfuhrabgabenbescheid) in your company's name for every shipment. The import VAT is claimed on the VAT return for the month of import, and that return is filed once the tax number arrives. Where you can, start the registration before the first shipment, and check that the customs papers name your company correctly.