Form 721: the border runs through the keys

The trigger

Form 721 is due from any tax resident whose combined virtual currencies held by third-party custodians outside Spain exceed €50,000 on 31 December — valued at that day's closing prices. The duty reaches the owner, the beneficial owner, authorised persons and anyone with power of disposal. The window runs 1 January to 31 March — a calendar of its own, separate from the Renta, and that separation is the first cause of misses. Once filed, you refile only if the 31 December balance grows by more than €20,000 over the last declaration, or if the qualifying condition ends.

The border: custody, not flag

What decides is not the exchange's logo but two questions: does a third party hold the keys? And is that third party outside Spain? Crypto at a Spain-registered entity stays outside the 721 even under a global brand. And self-custody — hardware wallet, software wallet, keys in your own hands — sits outside the form by design: with no custodian, there is no "situated abroad" to report. The same portfolio can enter or leave the form with a simple custody transfer — which turns every December transfer into an act with reporting consequences.

Canada asks where the platform is; Spain asks who holds the keys. It is the cleanest dividing line of any foreign-holdings form on this site — and people still cross it without noticing.

Penalties: after the judgment

The 721 was born in the shadow of Form 720 — whose disproportionate penalty regime the European court struck down in 2022. The result: failures are today sanctioned under the general regime of the tax code — per-datum fines with moderate minimums and caps, gradable and reducible on agreement. Far from the old 720 terror, but real, annual and cumulative — and a persistent 721 omission is, besides, the worst possible introduction when DAC8 data reveals the portfolio the form kept quiet.

What to do, by situation

1. Never crossed €50,000 with foreign custodians: no duty. Keep the 31 December valuation that proves it — the burden of evidencing the threshold is yours.
2. Over the line this year: file between January and 31 March, at 31 December closing prices from one stable source. Note the €20,000 rule for later years.
3. Past years unfiled: spontaneous late filing limits the damage versus a demand — and folds naturally into a regularisation that squares the Renta and the forms together.
4. December custody moves: document date and destination. Entering or leaving the form via a transfer is legitimate; appearing to have done it to hide is not.

The duty depends on facts this page does not know — custody, situs, thresholds. It frames the rule; it does not apply it to your case, and reading it creates no professional relationship.