In Denmark we have this (prefilled forms). Both for last years taxes and a preform for nexy years taxes. Income, tax, estate, interest, stock gains, and even tax exemption for commutes and similar are all filled out.

You simply login with your "easy id" and accept or edit.

Any oustanding balance in your favour is transferred to your bank account in about a week.

Any outstanding balance in the goverments favour will either be moved to next years taxes or billed automaticly dependant on the amount.

It all works out pretty good.. Even though we pay the worlds highest taxes.. (Sales tax 25%, car tax 180%, income tax 58%..)

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