What if the buying company is foreign?

It depends on whether it has its own legal personality. The pre-acquisition RCTR declaration duty, set out for entities not managed from Spain or the EU, is intended for structures without legal personality (trusts and comparable arrangements). A foreign company with its own legal personality does not normally fall under that specific duty and may be absent from the register entirely — in which case you need to request the corporate documentation directly.

The two cases are worth keeping apart:

1. A company with its own legal personality — a Ltd. or Corp. registered in Jersey or Delaware, say. Precisely because it has legal personality, it does not normally fall under the RD 609/2023 duty. In practice it often does not appear in the RCTR at all: it is neither a Spanish legal entity nor necessarily managed from Spain or the EU. The documentation then has to come from the commercial registry of its home jurisdiction.
2. A structure without legal personality — trusts and comparable arrangements. Here the pre-acquisition RCTR declaration duty clearly applies. In Anglo-Saxon estate planning this is considerably more common than a direct corporate purchase.

Where intermediate companies are involved, beneficial ownership can be indirect — the full chain of control must be documented, not just the first level.

Legal basis: Real Decreto 609/2023 (RCTR); Ley 10/2010, Art. 4; Real Decreto 304/2014, Art. 8

Practical tip: Assuming every foreign company is in the RCTR or subject to the same duty is a typical mistake. With these buyers an empty register search is not a finding but the norm — and no reason to skip requesting the documentation.