Adrian MM. May 23:

Mercantile = Trade Registry vs. Companies House Better tread carefully: inscripción registro mercantil is a Trade Registry entry encompassing far wider categories than companies, but also ordinary and general partnerships (search for the latter in *E&W* by UK VAT registration or at the local Chamber of Commerce), Economic Interest Groupings and sole (UK) trades (US) proprietorships.

I used to do personal, onsite searches in both Madrid and London where Partnerships had once been registered at the Registry of Business Names (for some nostalgic ? reason until recently, a common English Bar Exam question), albeit Limited Partnerships and now LLPs are regd. at Companies House, London https://discovery.nationalarchives.gov.uk/details/r/C329

Andy Watkinson May 23:

If I'm not mistaken, "diario" here refers to the Diario Oficial del BORME.
BORME (Boletín Oficial del Registro Mercantil). BORME. Diario oficial.

So it's the "Boletín" itself.

As far as "Mercantile Registry" is concerned, I'd take a look at R. Jower's explanation as to why this may not be the best rendering.

https://www.proz.com/kudoz/spanish-to-english/accounting/426...

philgoddard May 23:

What's the context? What do the Xs represent, and what is the 'instancia'?

Justin Peterson (asker) May 23:

That's a totally different kind of diario No, this is a category at the Mercantile/Business Registry ... not a state gazette.

Joss Heywood May 23:

Maybe an Official Gazette? Try Googling "Diario xx" Madrid.