Portugal has four main document types service professionals issue: invoice, invoice-receipt, receipt, credit note. Knowing when to use each prevents tax-authority issues, gives the client confidence, and saves you conversations with the accountant. This guide answers every question we see repeatedly from independent business owners.
The 4 documents: decision table
| Document | When to issue | Tax ID required? |
|---|---|---|
| Simple receipt (REC) | End client pays, doesn't want invoice with tax ID | No |
| Invoice-receipt (FAT-REC) | Service provided and paid at the moment, client wants tax ID | Yes, normally |
| Invoice (FAT) | Service provided, payment deferred or package | Yes |
| Credit note (NC) | Cancel or correct already-issued document | Same as original document |
Receipt: the minimum document
Simple receipt is what you give when the client says I don't want an invoice, just proof. Includes:
- Provider identification (your name, tax ID, address).
- Description of service provided.
- Amount paid and payment method.
- Issue date.
- Sequential numbering.
Invoice-receipt: the common case in services
It's the combination of invoice (proves provision) and receipt (proves payment). In B2C with immediate payment, it's what you almost always issue when the client wants proof with tax ID (to deduct tax, for company vouchers, for insurance).
- Full provider identification (tax ID, address, fiscal regime).
- Client identification (name + tax ID + address).
- Clear service description (Physio consultation, Cut and beard, etc.).
- Quantity, unit price, total, VAT (if applicable).
- Payment method, date, numbering.
Invoice (without receipt): installment cases
Rarer in B2C services, but common in specific cases:
- Company client paying at 30 days (monthly retainer).
- Service provided but payment delayed (client pays next week).
- Packs or retainers where monthly invoice sums multiple installments.
- After payment, you can issue a separate receipt (linked to that invoice).
Credit note: cancel or correct
Document already issued but there was an error (wrong price, wrong tax ID, service cancelled post-issue)? You can't edit - issue a credit note that cancels the original.
Identify the original document
Invoice-receipt no. 2025/0123 issued on 03/15.
Issue credit note referencing the original
BookHero generates NC linked to the original document automatically.
If full cancellation: issue NC at full negative value
Original document is cancelled for accounting purposes.
If correction: issue NC + new correct invoice-receipt
Cancel the wrong, issue the correct. Both stay logged.
BookHero: informational documents vs certified
Important to understand the distinction:
| Aspect | Informational documents (BookHero) | Certified tax-authority software |
|---|---|---|
| Sequential numbering | Yes | Yes, with TA key |
| Immutable snapshot | Yes | Yes |
| Full fiscal validity | Covers 95% of practical cases | Always |
| Automatic tax-authority reporting | No | Yes (monthly SAF-T) |
| Annual revenue limit | Defined by tax authority - check with accountant | No limit |
| Cost | Included in the plan | Additional software |
When you really need certified tax-authority software
General rule in Portugal: above a certain annual revenue threshold, or in certain accounting regimes, you need software certified by the tax authority to issue documents with full fiscal validity. The rules change (and depend on regime - simplified, organized, etc.) - confirm with your accountant.
Typical cases by client type
| Client | Typical document | BookHero handles? |
|---|---|---|
| Individual without tax-ID interest | Receipt (REC) | Yes |
| Individual wanting to deduct tax | Invoice-receipt with tax ID | Yes |
| Company paying at the moment | Invoice-receipt with company tax ID | Yes |
| Company paying at 30 days | Invoice, then separate receipt | Partially (trend: external fiscal software) |
| Client for insurance / health fund | Invoice-receipt with tax ID and precise description | Yes |
| Foreign client without PT tax ID | Receipt or invoice-receipt without tax ID | Yes |
Common issuance errors
- Issuing invoice without client's tax ID when they asked - document invalid for deduction.
- Changing service name after issuance - causes history inconsistency.
- Not numbering sequentially - breaks fiscal obligations.
- Issuing document after charging (instead of at the moment) - creates mismatch.
- Not referencing credit note to original document - accounting gets confused.
FAQ
Can I use BookHero as my single billing software?
For those below revenue thresholds the tax authority defines for mandatory certification, yes. For those above, BookHero serves operationally (organization, client receipts) and integrates with certified fiscal software for final issuance.
What document prefixes does BookHero use?
FAT (invoice/invoice-receipt), COR (correction/credit note), EC (cash in), SC (cash out). Configurable in Settings - choose yours to align with your accountant.
Can I issue a document without the client's tax ID?
Yes - issue a simple receipt (REC) or invoice-receipt without tax ID (goes as End consumer). There are annual revenue limits without identification that the tax authority defines - confirm with accountant.
What if I make a mistake on the document - can I edit?
No. Documents are immutable after issuance (snapshot). To correct, issue a credit note (cancels the original) and a new correct document. This is the right fiscal rule - not a software limitation.
Client asked for a duplicate of an old invoice - can I resend?
Yes. Go to Transactions, open the document, download the PDF and send. The original document stays unchanged (snapshot).