Óbolo · a Pluton product
Invoices that do not get rewritten.
Every issue and every cancellation leaves a hash and joins the chain. Built for VERI*FACTU (RD 1007/2023). Issued records are not deleted.
Invoice · example
F-2026-0142
20-09-2026
€1,234.56
Automatic submission to the Spanish tax agency
Hash
3C464DAF61ACB827C65FDA19F352A4E3
Chained from F-2026-0141
Records are not edited. An entry that should not exist is cancelled; wrong data is fixed with a corrective invoice.
How it works
Three steps. The record does not go backwards.
The mock-up is illustrative. What you cannot do is delete or rewrite an invoice already issued.
- 01
Issue
A registration with number, date, type and amount. The first record for each tax ID has an empty previous hash.
- 02
Chain
The SHA-256 hash follows the official AEAT format. Each record points to the previous one. One chain per issuer.
- 03
Send or sign
VERI*FACTU mode: submit to the tax agency. Non-VERI*FACTU mode: signed XML and local custody. Fixing means cancelling or correcting, never deleting.
F-2026-0141
Hash 3f9a…c21e
860,00 €
Tax agency 10:02
F-2026-0142
Hash 8b17…e04d
1.234,56 €
Tax agency 11:21
F-2026-0143
Hash c5d2…91af
412,30 €
Tax agency 12:47
F-2026-0144
Hash e71b…40c3
2.090,00 €
Tax agency 13:15
Features
What Óbolo does.
Real immutability: the database refuses to change or delete a record.
Insert only.
No UPDATE or DELETE on issued invoices. An entry that should not exist is cancelled; a real sale with wrong data is fixed with a corrective invoice.
One chain per tax ID.
Each issuer has its own sequence. The hash is recomputed on save. If it does not match, the record is rejected.
Cancel is not delete.
A cancellation is a new record, with its own hash, linked to the previous one. The original invoice stays.
Two modes, one record.
Automatic submission to the tax agency, or local signing and custody. The mode does not make the record mutable.
From quote to payment
More than the record.
Óbolo covers day-to-day invoicing. Anything that is not an invoice stays out of the chain and does not use a tax number.
Quotes
Their own series, 30-day validity by default and notes on the PDF. Editable while open. An accepted quote becomes an invoice or a proforma.
Proformas
Not submitted to the tax agency and no tax QR code. Add the customer later and turn it into an invoice when it is due.
Recurring invoices
Monthly, quarterly or yearly. Issued automatically on the set day. Pause or skip a period, and a failed run is retried.
PDF and email
A4 PDF with tax QR code, logo, address, VAT breakdown and payment terms. Sent from Óbolo, with the mail server response kept.
Customers and catalogue
Spanish tax IDs checked for their control digit and against the tax agency census with your certificate. Payment terms per customer.
VAT, exempt and simplified
21, 10, 5 and 4 % rates. Exempt operations with their reason and the legal wording on the PDF. Simplified invoices up to €400, or €3,000 in the cases of article 4 of the Spanish invoicing regulation. Óbolo works out the totals from the lines.
Signed backups
System backups are signed. An unsigned or altered backup is not restored, and every restore is logged.
Corrections without gaps
If the tax agency rejects an entry or accepts it with errors, it is resubmitted under the same number. The series stays unbroken.
API and integrations
Invoice from your own system.
Your online shop, ERP or booking tool issues invoices through the API, under the same rules as the dashboard: Óbolo sets the totals and the hash.
- Test and live keys
- The test key validates and returns the expected number without recording anything or calling the tax agency. The live key issues like the dashboard. The secret is shown once.
- No duplicate invoices
- Every POST carries an Idempotency-Key. For 24 hours, the same key with the same body returns the stored response.
- Signed webhooks
- Events for issued and cancelled invoices, tax agency submission status, quotes and proformas. HMAC-SHA256 signature and retries if your system does not answer.
- Per-key permissions
- Each key carries only what it needs: invoices, customers, quotes or proformas, read or write.
POST /v1/invoicesAuthorization: Bearer obolo_sk_test_…Idempotency-Key: pedido-8841 # webhookX-Obolo-Event: invoice.issuedX-Obolo-Signature: v1=…Endpoints for invoices, customers, quotes and proformas, with their PDF.
Talk about an integration →Required by regulation
A billing system is not a spreadsheet with macros.
RD 1007/2023 requires integrity, traceability and inalterability. VERI*FACTU is the continuous-submission mode. Óbolo is built for that frame.
- Companies: 1 Jan 2027
- Corporate-tax payers must have an adapted system before that date.
- Self-employed: 1 Jul 2027
- Everyone else, including personal-income tax on economic activity, follows six months later.
- Software, since 2025
- Vendors of invoicing software already had to offer adapted systems from 29 July 2025.
- Up to €50,000
- Using non-compliant software can be fined up to €50,000 per tax year.
01
2023 regulation
RD 1007/2023 sets how an invoicing computer system must behave. Saving a PDF is not enough.
02
2027 deadlines
Companies before 1 January 2027. Self-employed and other obligated parties before 1 July 2027. Use in 2026 is voluntary.
03
Official hash
The tax agency publishes the hash format and worked examples. Óbolo uses that format, not an invented concatenation.
04
It is not rewritten
A registered invoice is not edited. If it should not exist, it is cancelled. If the sale was real and some data was wrong, a corrective invoice is issued.
Compliance sits with the issuer. Óbolo leaves the trail.
Talk to usPrice
Priced for how you invoice.
Óbolo is scoped by invoice volume, issuers and integrations. Write to us and we will prepare the proposal.
Talk to us- 01
A proposal built for you
Tell us how you invoice and we will prepare it for your case.
- 02
By scope
Issuers, volume and whether accounting software needs a connector change the proposal.
- 03
You can start small
One tax ID, one flow, then expand. No rigid lock-in by default.
Is Óbolo ready for VERI*FACTU?
Yes. VERI*FACTU is the tax agency's mode in which every record is sent straight away. Óbolo can work that way or in the other mode the rules allow: signing and keeping the records.
Which mode do I start in?
Every account starts in VERI*FACTU. The sign-and-keep mode is switched on in Settings once the certificate is uploaded. In both, the record cannot be altered.
Does it replace my accounting software?
No. Óbolo covers invoicing and the record the tax agency requires. It is not an accounting package or an all-in-one business system.
Can I delete an invoice if I make a mistake?
No. If the entry should not exist, it is cancelled with a chained cancellation record. If the sale was real but some data is wrong, it is fixed with a corrective invoice (R1 to R4, or R5 if the original is simplified). The original stays in the chain.
Does it do quotes and proformas?
Yes. Neither is an invoice: they stay out of the chain, are not submitted to the tax agency and carry no tax QR code. An accepted quote becomes an invoice or a proforma, and a proforma becomes an invoice.
Can it connect to my online shop or business software?
Yes, through its API. You get a test key that records nothing, a live key to issue for real and a signed notification every time an invoice is issued.
Where is the data hosted?
In the European Union, on infrastructure we run ourselves. Your invoices never go through third-party tools.
How much does it cost?
It depends on how many businesses invoice, the volume and the integrations. Get in touch and we will prepare a proposal.
Start
Shall we talk about Óbolo?
Tell us how you invoice today. We will say if it fits and what the next step looks like.