Yes, eHerkenning EH3 is suitable for filing your dividend tax return. You can apply for a regular EH3 eHerkenning, but the Limited Belastingdienst EH3 is also suitable for this purpose.
If you already have a regular eHerkenningmiddel but do not have an authorization for Dividend tax return yet, you can add an additional authorization to your eHerkenning by logging in to My Reconi.
If you already have the Belastingdienst EH3 means, you do not need to add anything to your eHerkenning tool. You will automatically have access and be able to log in to the Tax Authorities Business for your Dividend.