guias
Brimlo Lab: turning AEAT requirements into product features
How a legal requirement moves from risk to data, validation and a clear action in the interface.
Brimlo Lab explains how a legal obligation becomes product mechanics. This is not a list of service promises or a sales demonstration. We show the reasoning, including its limits.
Start with the obligation, not the screen
“Add invoicing” is too vague. We first separate verifiable events: transaction date, counterparty, place of supply, supporting document and the ledger that receives the record. Only then does an interface make sense.
Sequential numbering → history without silent deletion
Invoices need series, gap control and traceability. A PDF button is not enough: corrections must preserve the original, create a linked rectifying invoice and connect the document to payment. Silently deleting an issued number may feel convenient, but it breaks the audit trail.
IVA depends on the transaction → classify before calculating
The customer's country does not determine IVA on its own. B2B or B2C status, VAT ID, service type and place of supply matter. The feature must collect that context before suggesting treatment. If data is missing, automation should stop and say what must be checked.
An expense needs evidence → connect document and record
A card payment does not make a cost business-related. Amount, category, invoice, supplier, date, purpose and business-use share belong to one evidence chain. That requirement produces source-file upload, review status and separate handling of depreciable assets.
Returns are connected → one data source
Modelo 303, 130, 349 and ledgers cannot behave as isolated calculators. One transaction may affect several reports. Changing the source record must update each dependent view and retain an explanation.
AEAT deadlines → a process, not one reminder
The official deadline is the final boundary. The working sequence starts earlier: collect evidence, find gaps, approve calculations, select payment, file and archive the receipt. The calendar becomes a quarter-close workflow rather than an alarm.
Where automation ends
A product can test completeness, consistency, arithmetic and known rules. It should not pretend to understand a disputed business purpose or complex international contract without more evidence.
The Brimlo Lab principle: automate repetition, explain the decision and clearly mark the point where human review is needed.
General information only; check your case against official sources or with a qualified professional.