Ninja Forms – Pro6PP Autofill by Treehugger.
What is Ninja Forms – Autofill Pro6PP
The addon Pro6PP Autofill for Ninja Forms is a smart and easy plugin to glue the Pro6PP API to Ninja Forms to let your customers fill within the paperwork with nice ease. With filling of their zipcode, the Pro6PP API shall be referred to as to fill in the remainder of the shape.
Note: Currently best the dutch API is named, however subsequent model will even hit upon belgium zipcodes.
Want to take a look at it out? Check the demo.