International secondment

Applying for an A1/certificate of coverage online


You can apply for an A1/certificate of coverage quickly and easily online using TWinternet. Compared to the paper form, there are far fewer details to fill in, and you will normally hear from us within a week. You can also track your application online.

Your representative, e.g. your tax consultant, can also submit an application online.

If your company does not yet have an account for online applications, you can apply for one. A few days after you have chosen a username, you will receive a letter from us containing your password. Keep your login details safe.

If you have forgotten your password

If you forget your password or username, you must apply for a new account. You will have to choose a new username.


If you, as an employer, have appointed a representative, you and your representative can both use your user name and password. In that case, we will not need a separate authorization.

However, if your representative also acts on behalf of your employee, we will need a signed authorization from your employee. You should send in the authorization by post, stating your employee's Burgerservicenummer (BSN). You should also state that the authorization is provided in connection with an application for an A1/certificate of coverage.
We advise you to send in the authorization one week before sending in your application for an A1/certificate of coverage so that we can process the application without delay.

NB: you need to submit an authorization with every new application.

Different procedure for employees living outside the Netherlands

If you have an employee who does not live in the Netherlands and who will be working in two or more EU Member States (including the Netherlands), you need to apply to the competent authority in the employee's country of residence for a statement that there are no objections to your employee being covered by Dutch social insurance legislation. You should then apply to us for an A1/certificate of coverage within two months, using a paper form and enclosing the statement by the non-Dutch competent authority.

Employers based outside the Netherlands

Online applications are not possible for companies based outside the Netherlands. In this case, you can download an application form (PDF, 1.1 Mb) and send it in by post.