Incorrectly issued invoice can lead to questions from the tax authorities, administrative penalties and even to non-deductibility of VAT charged. One of the invoice requirements that apply in all EU Member States is that the full legal name and address of both supplier and customer need to be mentioned on the Invoice (exceptions apply to simplified invoices). Full address means the address of the establishment that renders the services or supplies the goods or where the legal entity is established. A care-of address can be used for example as bill to address, but in addition the ‘real’ address should always be included.
In 2015 the German Federal Court Case ruled that also the use of a PO box cannot be seen as the full legal address.
When the PO box address is mentioned, the invoice might not be invalid. The full legal address of the supplier and the customer (where the business activities are carried out) have to be included on the invoice.
Your accounts receivable/payable departments should be checking invoices on these elements to avoid challenges on the validity of invoices received/issued.