Question 1

What is VeriFactu?

Accepted Answer

VeriFactu is Spain's regulation requiring all business invoices to be digitally registered with AEAT (Agencia Tributaria) in real time, with cryptographic hash chains to prevent tampering. AEAT Sync automates the entire process via a simple API.

Question 2

How do I send invoices to AEAT via API?

Accepted Answer

Make a single POST request to the AEAT Sync API with the invoice details (issuer NIF, items, VAT rates). AEAT Sync generates the VeriFactu XML, computes the hash chain, signs it with your digital certificate, and submits it to AEAT. You receive a webhook confirmation when AEAT accepts or rejects the invoice.

Question 3

Do I need to comply with Spanish e-invoicing laws?

Accepted Answer

Yes. All businesses operating in Spain must comply with VeriFactu regulations. Every invoice issued must be registered with AEAT in the required XML format with a tamper-proof hash chain. AEAT Sync handles this automatically so you don't have to build the compliance layer yourself.

Question 4

What is the hash chain in VeriFactu invoicing?

Accepted Answer

Each invoice includes a SHA-256 fingerprint of itself and the previous invoice, creating a cryptographic chain. If any invoice is modified or deleted, the chain breaks — proving tampering. AEAT Sync manages this chain automatically for each tenant.

Question 5

Can I integrate AEAT Sync with Stripe or other payment processors?

Accepted Answer

Yes. The typical flow is: your payment processor fires a webhook when a payment succeeds, your server calls the AEAT Sync API with the invoice data, and AEAT Sync handles submission to AEAT and notifies you back via webhook. This works with Stripe, GoCardless, Redsys, PayPal, or any processor.