NAP stands for name, address and phone number: the basic details of a business. They are the details a customer, a search engine or an AI assistant uses to recognise and reach your business. NAP consistency means using exactly the same details, written the same way, everywhere they appear. In local SEO, that consistency is the main point.
Why does it matter?
Your details appear in many places: your website, your Google Business Profile, your Organization schema, social profiles and business directories. In its guidelines for business profiles, Google asks for your real business name, as used on your shopfront, website and stationery, a precise address and a phone number that belongs to that location. Conflicting details make it harder to tell which information is correct.
Example
Say a dental practice moves from Kerkstraat to Stationsweg. The website shows the new address, but the business profile and two directories still list the old one. A patient navigating with Maps ends up in front of an empty building. Updating the details everywhere at the same time prevents that.
Common mistake
Small differences you do not notice yourself: the Dutch company suffix “B.V.” in the name or not, an old 0900 number (a Dutch premium-rate line), or “Stationsweg 4a” versus “Stationsweg 4 A”. Stick to one fixed spelling. How to go about it is covered in Make sure search engines and AI know who you are: business information and Organization schema.