Frequently asked questions about TWinternet

You can apply online for a TWinternet account using eHerkenning. You will need your payroll tax number (loonheffingennummer), and your Chamber of Commerce number (KVK-nummer) and branch number (vestigingsnummer). 

To log in to TWinternet, you need eHerkenning (level EH3).

Register your foundation or association with the Dutch Chamber of Commerce (KvK). After you have registered, you can apply for a TWinternet account online using eHerkenning.

Before we can finish processing your application, we always check whether the posting period is correct and your employee meets all the necessary conditions. 

Sometimes, we need more information, for example because another certificate has been issued for the same period. In that case, we will need to contact you, and your application will not yet appear in the status overview.

You will not be able to apply for an A1 certificate online if your business is based outside the Netherlands. Instead, you can download the application form and send it to us by post.