Do you have a sole proprietorship? In that case, you can expect a letter from the Dutch tax office shortly. The letter will mention a new Dutch VAT-identification number that is no longer related to your citizen service number (so-called: BSN).
You must use this new VAT-identification number from 1 January 2020 in all your communications with customers and suppliers. We therefore advise you to adjust all business communication in time to this new number, such as invoices, website, letterhead, etc.
The current / old VAT-number (including your citizen service number) remains necessary for contacts with the tax authorities and for filing your VAT returns.