Contact and publisher details

Last updated 2026-08-22

Write to the editor

Write to [email protected]. The form below is switched on once the publisher's form key is in place; the address works either way.

What gets answered, and how fast

• Corrections and factual queries. These come first. If you can name the page and quote the sentence, I can usually verify it against the source and fix it within a few days. If you are right, the article is corrected and marked as revised.
• Questions about an article. Answered where the answer is general. I cannot advise on whether a particular entity is in scope of a particular mandate, and I will say so rather than guess. See the disclaimer.
• Advertising and sponsorship. Display advertising is served programmatically and there is nothing to negotiate. Anything else is covered by the advertising disclosure — read it before writing, because it rules out most of what is normally proposed.
• Rights, privacy and data requests. Handled under the privacy policy. Requests under the GDPR are answered within one month.
• Unsolicited guest posts, link insertions and "content partnerships". These are not accepted, in any form, at any price. There is no need to follow up.

Publisher details

Provided in compliance with the information requirements of Spanish Law 34/2002 on information society services and electronic commerce.

The full tax identification number of the publisher is not printed on this site. Two reasons, and they are both deliberate.

The first is ordinary caution: a published national identification number is enough for somebody to open an account in another person's name, and the obligation to publish one applies to providers carrying on a registered economic activity. The second is specific to the subject. This site writes about tax obligations. Printing a tax number beside that analysis invites it to be read as advice given by a registered professional, which is precisely what the disclaimer says it is not.

Full identification is provided on request to anyone with a legitimate interest, including any competent authority.

Press and speaking

Happy to answer questions from journalists working on e-invoicing mandates, and to point at the primary sources rather than at my own summary of them. I do not provide quotes endorsing products.

What I will not do

• Confirm that a specific implementation is compliant.
• Review a vendor's marketing material.
• Provide a backlink in exchange for anything.
• Accept a draft article written by somebody else.