Build the SAF-T (PT) File (Standard Audit File for Tax — Portugal)

Skill: Convert invoicing and accounting data into the SAF-T (PT) XML

Region: Portugal Category: SAF-T (PT) — Standard Audit File for Tax, Autoridade Tributária e Aduaneira (AT) Does: Takes a firm's invoicing and/or accounting data and produces the AuditFile XML defined by the Portuguese SAF-T (PT) schema — Header, MasterFiles (Customers, Products, TaxTable), GeneralLedgerEntries, and SourceDocuments/SalesInvoices, with each invoice carrying its ATCUD, the 4-character document Hash from the certified signature chain, and the TaxCountryRegion/TaxCode breakdown. Schema version: urn:OECD:StandardAuditFile-Tax:PT_1.04_01 (Portaria n.º 302/2016, current AT XSD SAFTPT1.04_01.xsd)

The SAF-T (PT) is an AT-prescribed audit/reporting file, not a real-time message. The monthly billing SAF-T (only Header + MasterFiles/Customers/Products/TaxTable + SourceDocuments/SalesInvoices) must be submitted on the Portal das Finanças (e-Fatura / "Comunicação de faturas por SAF-T") by the 5th of the month following issue; the full accounting SAF-T (adding GeneralLedgerEntries and MovementOfGoods/WorkingDocuments/Payments) is generated annually on request or for an inspection (IES support). The AI assembles the XML from already-certified records — it cannot generate a valid invoice Hash, which is produced by the certified billing software's RSA-SHA-1 signature chain. Validate against the current SAFTPT1.04_01.xsd before submission.

When this applies

• Any taxpayer using certified invoicing software in Portugal must export issued invoices monthly as a billing SAF-T (PT) for the AT (SAFTmode = billing). This is the most common case and the focus of the worked example.
• Organised-accounts taxpayers must be able to produce the full accounting SAF-T (PT) (SAFTmode = accounting) covering GeneralLedgerEntries, supporting the annual IES/DA declaration.
• An integrated export (SAFTmode = integrated) combines both.
• Excluded: simplified-regime taxpayers below the certification threshold (who may report invoices manually on e-Fatura), and non-Portuguese establishments without a Portuguese NIF.

Conversion procedure

1. Read the source. Accept the invoicing/accounting export as CSV, JSON, the ERP's own XML, or pasted text. Parse customers, products, tax rates, and each invoice with its lines. For an accounting SAF-T also read the journal/ledger entries.
2. Extract fields. For every invoice capture: number (InvoiceNo in the form Type Series/Seq, e.g. FT A/123), ATCUD, InvoiceDate, InvoiceType, customer ID, each line's quantity/unit price/tax, and the document totals. For each customer/product build the MasterFiles entries. If any required field — especially the ATCUD or the line Hash chain — is missing, stop and ask; never invent them.
3. Normalize. Dates → YYYY-MM-DD; date-times → YYYY-MM-DDThh:mm:ss; the Portuguese NIF is 9 digits, prefixed in CustomerTaxID/SupplierTaxID only where the schema's country-qualified ID is used; amounts → dot decimal, generally 2 decimals (unit prices may carry up to the schema-allowed precision); TaxCountryRegion = PT (or PT-AC Açores / PT-MA Madeira); TaxPercentage as a plain number (23, 13, 6, 0).
4. Compute. Recompute every line CreditAmount (net), per-rate tax, DocumentTotals/TaxPayable, NetTotal, and GrossTotal; reconcile against the source and flag mismatches. Do not recompute the cryptographic Hash — copy the certified value verbatim (4-char Hash field is the 1st, 11th, 21st and 31st character of the full Base64 signature).
5. Emit the output. Build the AuditFile per the structure below. For a billing SAF-T omit GeneralLedgerEntries, MovementOfGoods, WorkingDocuments, and Payments unless present; always include Header, MasterFiles, and SourceDocuments/SalesInvoices.
6. Validate. Work through the checklist; confirm TaxRegistrationNumber, TaxEntity, SAFTmode, and per-invoice ATCUD/Hash are present and well-formed.

Source → SAF-T (PT) field map

Every required output element appears above. Repeat Customer, Product, TaxTableEntry, Invoice, and Line once per occurrence.

Document structure

AuditFile (xmlns urn:OECD:StandardAuditFile-Tax:PT_1.04_01)
├── Header                                        (once)
│   ├── AuditFileVersion                          (1.04_01)
│   ├── CompanyID
│   ├── TaxRegistrationNumber                     (9-digit NIF)
│   ├── TaxAccountingBasis                        (F | C | I | S | P | R | E | T)
│   ├── CompanyName
│   ├── BusinessName / CompanyAddress
│   ├── FiscalYear / StartDate / EndDate
│   ├── CurrencyCode                              (EUR)
│   ├── DateCreated
│   ├── TaxEntity                                 (Global / cost-centre id)
│   ├── ProductCompanyTaxID
│   ├── SoftwareCertificateNumber                 (AT certificate number)
│   ├── ProductID                                 (Product/Producer)
│   └── ProductVersion
├── MasterFiles                                   (once)
│   ├── Customer ...                              (one per customer)
│   ├── Product ...                               (one per product/service)
│   └── TaxTable
│       └── TaxTableEntry ...                     (one per TaxCountryRegion + TaxCode + %)
├── GeneralLedgerEntries                          (accounting SAF-T only — omit for billing)
│   └── Journal / Transaction ...
└── SourceDocuments                               (once)
    └── SalesInvoices
        ├── NumberOfEntries
        ├── TotalDebit
        ├── TotalCredit
        └── Invoice ...                           (one per invoice)
            ├── InvoiceNo                          (e.g. "FT A/123")
            ├── ATCUD                              (validation-code-series + "-" + seq)
            ├── DocumentStatus (InvoiceStatus / InvoiceStatusDate / SourceID / SourceBilling)
            ├── Hash                               (4 chars from RSA-SHA-1 signature chain)
            ├── HashControl
            ├── Period                             (month 1–12)
            ├── InvoiceDate
            ├── InvoiceType                         (FT, FS, FR, ND, NC…)
            ├── SpecialRegimes (SelfBillingIndicator / CashVATSchemeIndicator / ThirdPartiesBillingIndicator)
            ├── SourceID / SystemEntryDate
            ├── CustomerID
            ├── Line ...                            (one per line)
            │   ├── LineNumber
            │   ├── ProductCode / ProductDescription / Quantity / UnitOfMeasure / UnitPrice
            │   ├── TaxPointDate
            │   ├── Description
            │   ├── CreditAmount   (or DebitAmount on credit notes)
            │   └── Tax (TaxType / TaxCountryRegion / TaxCode / TaxPercentage)
            └── DocumentTotals (TaxPayable / NetTotal / GrossTotal)

Notes: MasterFiles/TaxTable is mandatory in every variant. GeneralLedgerEntries appears only when TaxAccountingBasis indicates accounting/integrated. Exempt lines carry TaxCode ISE with TaxPercentage 0 and a TaxExemptionReason + TaxExemptionCode (e.g. M07) on the line.

Code tables

TaxAccountingBasis (Header — the "SAFTmode")

InvoiceType

TaxType and TaxCode

Selected TaxExemptionCode (when TaxCode = ISE)

Calculation rules

• Line net (CreditAmount) = Quantity × UnitPrice (less any line discount), rounded to 2 decimals.
• Line VAT = line net × TaxPercentage ÷ 100, rounded to 2 decimals.
• DocumentTotals/TaxPayable = Σ line VAT across all rates, 2 decimals.
• DocumentTotals/NetTotal = Σ line net (CreditAmount), 2 decimals.
• DocumentTotals/GrossTotal = NetTotal + TaxPayable, 2 decimals.
• SalesInvoices/TotalCredit = Σ all invoices' net credit; TotalDebit = Σ debit (credit notes); NumberOfEntries = count of Invoice elements.
• Hash (4 chars): characters at positions 1, 11, 21, 31 of the full Base64 RSA-SHA-1 signature of InvoiceDate;SystemEntryDate;InvoiceNo;GrossTotal;PreviousHash. Never recompute or guess — copy from the certified software. Flag if absent.
• ATCUD = <validation-code-of-series>-<sequential number within series> (e.g. AAJFF7VFKR-123). The validation code is issued by the AT per series; the sequence equals the numeric part of InvoiceNo.
• Amounts in EUR, dot decimal, 2 decimals, no thousands separators.

Worked example (end-to-end billing SAF-T fragment)

Exemplo Comércio Lda (NIF 501234567, AT software certificate 1234) issues one full invoice FT A/123 on 2026-06-05 to customer Cliente Final Lda (NIF 502345678): 1 unit of product P001 ("Serviço de consultoria") at net 1000.00, VAT NOR 23% → TaxPayable 230.00, GrossTotal 1230.00. Series A has AT validation code AAJFF7VFKR, so ATCUD = AAJFF7VFKR-123. The certified signature's 4-char Hash is JpRm.

<?xml version="1.0" encoding="UTF-8"?>
<AuditFile xmlns="urn:OECD:StandardAuditFile-Tax:PT_1.04_01" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="urn:OECD:StandardAuditFile-Tax:PT_1.04_01 SAFTPT1.04_01.xsd">
  <Header>
    <AuditFileVersion>1.04_01</AuditFileVersion>
    <CompanyID>501234567</CompanyID>
    <TaxRegistrationNumber>501234567</TaxRegistrationNumber>
    <TaxAccountingBasis>F</TaxAccountingBasis>
    <CompanyName>Exemplo Comercio Lda</CompanyName>
    <CompanyAddress>
      <AddressDetail>Rua das Flores 10</AddressDetail>
      <City>Lisboa</City>
      <PostalCode>1200-001</PostalCode>
      <Country>PT</Country>
    </CompanyAddress>
    <FiscalYear>2026</FiscalYear>
    <StartDate>2026-06-01</StartDate>
    <EndDate>2026-06-30</EndDate>
    <CurrencyCode>EUR</CurrencyCode>
    <DateCreated>2026-07-02</DateCreated>
    <TaxEntity>Global</TaxEntity>
    <ProductCompanyTaxID>509999999</ProductCompanyTaxID>
    <SoftwareCertificateNumber>1234</SoftwareCertificateNumber>
    <ProductID>FaturaPro/Exemplo Software Lda</ProductID>
    <ProductVersion>3.2</ProductVersion>
  </Header>
  <MasterFiles>
    <Customer>
      <CustomerID>C001</CustomerID>
      <AccountID>Desconhecido</AccountID>
      <CustomerTaxID>502345678</CustomerTaxID>
      <CompanyName>Cliente Final Lda</CompanyName>
      <BillingAddress>
        <AddressDetail>Avenida Central 22</AddressDetail>
        <City>Porto</City>
        <PostalCode>4000-002</PostalCode>
        <Country>PT</Country>
      </BillingAddress>
      <SelfBillingIndicator>0</SelfBillingIndicator>
    </Customer>
    <Product>
      <ProductType>S</ProductType>
      <ProductCode>P001</ProductCode>
      <ProductDescription>Servico de consultoria</ProductDescription>
      <ProductNumberCode>P001</ProductNumberCode>
    </Product>
    <TaxTable>
      <TaxTableEntry>
        <TaxType>IVA</TaxType>
        <TaxCountryRegion>PT</TaxCountryRegion>
        <TaxCode>NOR</TaxCode>
        <Description>Taxa normal IVA 23%</Description>
        <TaxPercentage>23.00</TaxPercentage>
      </TaxTableEntry>
    </TaxTable>
  </MasterFiles>
  <SourceDocuments>
    <SalesInvoices>
      <NumberOfEntries>1</NumberOfEntries>
      <TotalDebit>0.00</TotalDebit>
      <TotalCredit>1000.00</TotalCredit>
      <Invoice>
        <InvoiceNo>FT A/123</InvoiceNo>
        <ATCUD>AAJFF7VFKR-123</ATCUD>
        <DocumentStatus>
          <InvoiceStatus>N</InvoiceStatus>
          <InvoiceStatusDate>2026-06-05T10:15:00</InvoiceStatusDate>
          <SourceID>admin</SourceID>
          <SourceBilling>P</SourceBilling>
        </DocumentStatus>
        <Hash>JpRm</Hash>
        <HashControl>1</HashControl>
        <Period>6</Period>
        <InvoiceDate>2026-06-05</InvoiceDate>
        <InvoiceType>FT</InvoiceType>
        <SpecialRegimes>
          <SelfBillingIndicator>0</SelfBillingIndicator>
          <CashVATSchemeIndicator>0</CashVATSchemeIndicator>
          <ThirdPartiesBillingIndicator>0</ThirdPartiesBillingIndicator>
        </SpecialRegimes>
        <SourceID>admin</SourceID>
        <SystemEntryDate>2026-06-05T10:15:00</SystemEntryDate>
        <CustomerID>C001</CustomerID>
        <Line>
          <LineNumber>1</LineNumber>
          <ProductCode>P001</ProductCode>
          <ProductDescription>Servico de consultoria</ProductDescription>
          <Quantity>1.00</Quantity>
          <UnitOfMeasure>UN</UnitOfMeasure>
          <UnitPrice>1000.00</UnitPrice>
          <TaxPointDate>2026-06-05</TaxPointDate>
          <Description>Servico de consultoria - junho 2026</Description>
          <CreditAmount>1000.00</CreditAmount>
          <Tax>
            <TaxType>IVA</TaxType>
            <TaxCountryRegion>PT</TaxCountryRegion>
            <TaxCode>NOR</TaxCode>
            <TaxPercentage>23.00</TaxPercentage>
          </Tax>
        </Line>
        <DocumentTotals>
          <TaxPayable>230.00</TaxPayable>
          <NetTotal>1000.00</NetTotal>
          <GrossTotal>1230.00</GrossTotal>
        </DocumentTotals>
      </Invoice>
    </SalesInvoices>
  </SourceDocuments>
</AuditFile>

Normalisations shown: TaxAccountingBasis F (billing-only SAF-T, so GeneralLedgerEntries omitted); date 05/06/2026 → 2026-06-05; status timestamp → 2026-06-05T10:15:00; rate 23% → 23.00; Line VAT recomputed 1000.00 × 23% = 230.00; NetTotal 1000.00; GrossTotal 1000.00 + 230.00 = 1230.00; ATCUD formed as AAJFF7VFKR-123; the 4-char Hash JpRm copied verbatim from the certified signature (not recomputed). This file is uploaded on the Portal das Finanças via the SAF-T invoice-communication channel by the 5th of the following month.

Validation checklist

• All required fields extracted; AI asked about anything missing or ambiguous (no invented NIFs, ATCUDs, dates, or amounts)
• Root AuditFile namespace = urn:OECD:StandardAuditFile-Tax:PT_1.04_01; AuditFileVersion = 1.04_01
• TaxAccountingBasis (SAFTmode) correct: F for billing-only (no GeneralLedgerEntries), C/I for accounting
• Header carries TaxRegistrationNumber (9-digit NIF), FiscalYear, StartDate/EndDate, SoftwareCertificateNumber, ProductID
• MasterFiles/TaxTable present with a TaxTableEntry for every TaxCountryRegion + TaxCode used
• Each Invoice has InvoiceNo (Type Series/Seq), a well-formed ATCUD (validation-code-series-seq), and the certified 4-char Hash
• InvoiceType and per-line TaxType/TaxCountryRegion/TaxCode are valid codes; exempt lines carry TaxExemptionCode/Reason
• Line VAT = net × TaxPercentage ÷ 100; TaxPayable, NetTotal, GrossTotal recomputed and reconciled, mismatches flagged
• NumberOfEntries = count of invoices; TotalCredit/TotalDebit reconcile with the lines
• Amounts EUR dot-decimal 2dp; dates YYYY-MM-DD, timestamps YYYY-MM-DDThh:mm:ss
• File validates against the current SAFTPT1.04_01.xsd before upload to the Portal das Finanças

Last updated: 2026-06-13 — verify the active SAF-T (PT) schema version (currently 1.04_01), the AT TaxCode/TaxExemptionCode lists, the ATCUD/series rules, and the monthly billing-SAF-T submission deadline against the current AT specification before use.