Recurring Invoices and Subscriptions Under VeriFactu: Automate Without Breaking the Chain

Recurring Invoices and Subscriptions Under VeriFactu: Automate Without Breaking the Chain

Retainers, monthly maintenance fees, software subscriptions, commercial rent: if your business runs on recurring revenue in Spain, you issue nearly identical invoices every month. Since Spain's invoicing systems regulation (Royal Decree 1007/2023) came into force — companies from 1 January 2026, self-employed workers from 1 July 2026 — that automated billing must happen inside a compliant SIF (certified invoicing system). Automation is still possible, and still the right call. What changes is how you set it up.

The hash chain does not allow shortcuts

Every invoice you issue produces a billing record with a SHA-256 hash chained to the previous record. It is a strict chronological chain: September's subscription record points to whatever invoice your system issued immediately before it, regardless of client or product.

The practical consequence for recurring billing: you cannot pre-generate invoices outside the system and import them later, and you cannot let a spreadsheet or template tool produce PDFs on the side. Automation has to run inside the SIF, which at the actual moment of issue computes the hash, generates the mandatory QR code and — if you operate in VeriFactu mode — transmits the record to the Spanish tax agency (AEAT) in real time. In non-VeriFactu mode, the signed record is stored locally together with the event log, ready to be handed over if the AEAT requests it.

Issue date vs accrual date

Recurring billing mixes two dates you must keep apart:

• Accrual date: when the service is actually provided (the September instalment).
• Issue date: when the invoice is really generated.

The billing record captures the actual issue date and time — the moment the system creates the record. If your automation fires on the 1st at 07:00, that timestamp is what gets chained. Backdating or forward-dating is off the table: the chain and the event log document the real moment of issue. If your business model requires invoicing in advance (rent billed at the start of the period, annual plans paid upfront), do it with a documented, consistent rule: same day of the cycle every time, with the accrual period stated clearly in the invoice line.

What if the price changes mid-contract?

A classic scenario: you apply an inflation-linked increase in July, but July's invoice already went out at the old rate.

• If the issued invoice was correct at the time and the new price applies from the next cycle, do nothing retroactive: the next invoice simply carries the new amount. That is a new invoice, not a correction.
• If the invoice went out with a wrong amount (misapplied increase, forgotten contractual discount), issue a corrective invoice (factura rectificativa), which creates its own linked billing record. Never edit or delete the original — inalterability is the whole point of the regulation, and every cancellation is logged as an event.

Direct debits and reconciliation

Collecting by SEPA direct debit does not change your invoicing duties, but the order of operations matters: issue the invoice in the SIF first, then build the debit batch from invoices already issued. Reconciliation becomes trivial — every returned debit maps to one specific invoice. If a payment bounces, you chase the payment; you do not touch the invoice, because non-payment is a collections issue, not an invoicing error.

Mistakes that are now expensive

• Duplicating series: running recurring and one-off invoices on the same series from different tools produces gaps or duplicate numbers. Use separate series (one for subscriptions, one for extras) and issue everything from a single system.
• Invoicing early without a rule: pulling billing forward "because I'm closing the month early" breaks cycle consistency and muddies the VAT period.
• Regenerating invoices: reissuing a corrected PDF without a corrective invoice was bad practice before; inside a SIF it is simply not possible to do legitimately.
• Deleting scheduled invoices already issued when a customer pauses a subscription: they must be voided with their own record, never erased.

The stakes are real: using non-compliant invoicing software can be fined up to €50,000 per financial year (Article 201 bis of the Spanish General Tax Law). The upside: a well-configured SIF turns recurring billing into what it should be — a process that runs itself, with a complete audit trail and no surprises.