Invoice construction work under inversion del sujeto pasivo

Read the contract for two facts: that there is a contract between a promotor and a contratista for the construction or refurbishment of a building, and that your own contract sits under it, directly or through another subcontract. Both have to hold before the reverse charge reaches your invoice.

Why: The rule is about the chain, not about the trade. The same crew doing the same work is inside it on a refurbishment under a main contract and outside it on a call-out repair for the same client, and nobody notices the difference until an inspection reads the two invoices side by side.

Create the determination for this invoice: the Spanish construction rule, the article it rests on, the sentence that goes on the document, the net amount and the fact that the buyer accounts for the VAT. The record will not leave draft while the wording is missing or a VAT amount is still sitting on it.

Why: Per invoice rather than per customer, because the same customer can be inside the rule on one job and outside it on the next. Recorded rather than remembered, because the question that arrives in an inspection is why this invoice carried no VAT, and the answer has to be a decision with a date and an article rather than a habit.

Raise the invoice for the net amount, put the statutory sentence naming the article on the face of it, and leave the VAT line empty rather than at zero percent. Reference the certificacion it answers so the two can be matched later.

Why: An invoice with the right total and no sentence is the one that gets returned, and returning it restarts the payment clock that was the whole point of certifying on time. A zero-rate line is not the same thing as no VAT either: it says a rate was applied, which is a different tax position from the one you meant.

File the customer's written statement that they are acting as a business in this transaction, together with their tax registration details, and link it to the invoices it covers. Keep it against the contract it was given for rather than against the customer, because the same customer can be outside the rule on the next job.

Why: The rule turns on the customer's status, and the customer is the only one who can state it. Without that statement on file the VAT you did not charge is VAT you may end up paying yourself, with the interest, years after the client has gone.

Send the invoice record to the authority under the Spanish reporting regime and keep the acknowledgement reference against it. The invoice is valid from the moment it is issued; the report is a separate obligation with a four calendar day window, and a correction is an annulment record followed by a corrected one.

Why: Late reporting is a penalty rather than an invalid invoice, which is exactly why it slides: nothing breaks and nobody chases it. It is also the cheapest thing on this list to keep on top of, because the window is short enough that either you have a routine or you have a fine.