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Box 3 filing

Prepare your Box 3 filing without losing the thread

Start with the Aangifte Copilot to surface Box 3 exposure first, then continue with the exact follow-up steps and calculators that matter for your filing.

Surface savings, investments and foreign-asset follow-up early

The copilot lets you declare Box 3 exposure up front so the filing review is not starting from a blank state.

Move from filing questions to the right Box 3 calculator only when needed

Belastbaar can then recommend the Box 3 calculator and related follow-up only when it is relevant to your case.

Keep manual-only document reminders visible while you fill the return

You keep a side-by-side overview of what is estimated, what is confirmed, and what must still be entered manually.

Frequently asked questions

What documents are most helpful for Box 3 preparation?

Year-end bank statements, broker statements, debt overviews, and supporting documents for crypto or foreign accounts are usually the most important.

Why not start directly with the Box 3 calculator?

Because the filing copilot first determines whether Box 3 is actually relevant and then puts the Box 3 follow-up in the wider filing context.