The call-off stock procedure is a simplification that allows you to avoid foreign VAT registrations.
Basically, setting up a warehouse at a customer’s place abroad requires the recognition of intra-community transactions at the level of movement of goods between EU countries (ICS / CTS) and then domestic supplies subject to local VAT or subject to a reverse charge (depending on the regulations of a given country). The process of registering for VAT in a foreign country is sometimes time-consuming and often requires the support of local tax advisors. This translates into adaptation time and cost.
Source Piotr Chojnacki