Self-employed? Include the Certificate of Coverage (Form A1) in your US Return
If you are self-employed, you must be able to show in your US tax return that you paid your social security contributions in the country where you live and pay taxes.
You can do this by including a “Certficate of Coverage” or an “A1” form with your US Return.
If you live in a European country other than the Netherlands, you must also demonstrate that you have paid your social security contributions in the country where you live and pay tax.
Click on this link for the contact address where this form can be requested in your country: https://europa.eu/youreurope/citizens/work/social-security-forms/contact_points_pd_a1.pdf
If you live and pay taxes in The Netherlands, you can find the application form to request Form A1 here, (for an English version click here). Print and fill out this form, and send it by post to the SVB (address at the bottom of the form).
You will notice that the questions in this form are not fully applicable to your situation as a US Person, because the SVB has not yet found a good solution for US Persons (the form is mainly used by people who work abroad). However, this is the correct and so far the only form with which you can obtain the required statement.
Examples from the past tell us that it is best to fill in “na, see attachment” for questions that do not apply to your situation, and to enclose a written declaration as an attachment explaining that you are a US Person and that you need to demonstrate in your American tax return that you are, or have been, insured for social security in the Netherlands during the period that you worked as a self-employed person (please make sure to send the requested attachments to the SVB that relate to your company, such as overviews of sales tax, to demonstrate that you were an entrepreneur).
The Certificate of Coverage / A1 that you will receive thereafter must be sent with your US tax return to the IRS, so please upload it in your online file as soon as you receive it.
If you would not request the Certificate of Coverage, there is a good chance that your US tax return will show that you have to pay tax in the US, because Social security is also taxed in the US for self-employment. However, because the US and most European countries have a tax treaty to prevent double taxation, you can use this Certificate of Coverage to demonstrate that you have already paid your social security contributions, in the country where you live and pay your taxes, for the period that you were self-employed.