CAE vs CIRS Portugal: What Activity Code Do You Actually Need as a Translator or Interpreter?

The search query "CIRS 1334 translator Portugal" or "activity code freelance interpreter Portugal" typically returns generic freelancer guides that don't address the actual confusion: the number 1334 refers to a CIRS Art. 151 code, not a CAE code, and the two systems have nothing in common beyond the professional domain they cover.

That distinction matters in practice. Your CIRS activity code governs your IRS coefficient, your withholding rate, and your entire simplified-regime tax calculation. Get it wrong, and you may be over-reporting taxable income every year or carrying an unrecognised misclassification liability. This post covers what CIRS 1334 actually means, who it applies to, and what the tax picture looks like when your clients are in London, Amsterdam, or Brussels.

Two systems with one shared purpose but nothing else in common

CAE (Classificacao Portuguesa de Atividades Economicas) is Portugal's implementation of the EU NACE classification. It is maintained by INE (Instituto Nacional de Estatistica), the national statistics office. CAE classifies economic entities: companies, associations, branches. When a translation agency forms as a Lda, it picks a CAE. CAE 74300 ("Traducao e interpretacao") is the code for a translation company.

CIRS Art. 151 is a list maintained by AT (Autoridade Tributaria e Aduaneira), the tax authority. It classifies individual independent professionals, the people Portugal calls trabalhadores independentes who issue Recibos Verdes. When you open your freelance activity at the Portal das Financas as a sole proprietor, you choose a code from this list.

Same domain, different universe. A translation agency picks CAE 74300. A freelance translator picks a CIRS Art. 151 code. Neither number works in the other system.

The CIRS glossary entry explains the broader context of how the Art. 151 table fits into Portuguese tax law.

What CIRS 1334 actually covers

Code 1334 in the Art. 151 table is "Tradutores e interpretes" (translators and interpreters). This covers both sides of the language-services profession:

Written translation across all specialisms: literary translators working on books and other text, technical translators handling engineering manuals and patents, legal translators producing certified translations of contracts and certificates, medical and life-sciences translators, and localization specialists adapting software and digital products for new markets.

Oral interpretation across all formats: consecutive interpreters working with a notepad in meetings and conferences, simultaneous interpreters in booths at large events, liaison interpreters accompanying business delegations or legal proceedings, and court interpreters.

Both activities fall under 1334. If your work combines translation and interpretation, you don't need two codes.

Three adjacent codes come up in the same searches as 1334.

CIRS 1320 ("Consultores"): consultants. If your primary activity has shifted to language consulting, terminology management advisory, or translation-quality advisory work where your deliverable is advice rather than a translated text, 1320 may apply. For most working translators and interpreters, the primary output is a document or interpretation session, not a strategic recommendation. See the CIRS 1320 guide.

CIRS 1327 ("Jornalistas e repórteres"): journalists and reporters. A small overlap exists for translators who produce editorial content for news organisations, but journalistic translation as a primary activity is uncommon enough that most people in this situation are filing primarily under one code or the other. See the CIRS 1327 guide if your work is primarily editorial.

CIRS 1519 ("Outros prestadores de servicos"): the catch-all for professions not specifically listed in the Art. 151 table. Its coefficient is 0.35, not 0.75. Translators and interpreters are specifically named in the Art. 151 table, so 1519 is not the right code. It may look attractive at first: 0.35 means only 35% of gross revenue is taxable, versus 75% under 1334. But it is a misclassification, and AT classifies income based on the activity you actually perform, not the code you filed. The exposure is reassessment at the correct coefficient plus penalties and compensatory interest for every year the misclassification ran.

The copyright layer

Translations are protected works under Portuguese copyright law (CDADC, Código do Direito de Autor e dos Direitos Conexos). A translated text is considered an obra derivada (derivative work): the translator holds copyright in the translation itself, separate from the original author's copyright in the source text.

For standard commissioned translation work, this doesn't change your tax coefficient. You produce a translation for a publisher, a law firm, or a company; they pay you a fee; that income is a service under CIRS 1334 at the 0.75 coefficient.

The question gets more interesting when you retain copyright in a translation and then license it separately. If you translated a novel for a publisher in Portugal and later the publisher sells rights to a Spanish edition using your Portuguese text, you may receive royalty income for the use of your translated work. That licensing income is closer to intellectual-property income than service income, and the relevant coefficient for IP licensing is 0.95 (higher, not lower than 0.75).

In practice: most working translators doing commissioned work are firmly in the service category. The IP angle matters mainly for book translators who retain contractual rights and can independently license the translation in new territories. If a significant part of your income comes from royalties or licensing arrangements rather than translation fees, raise this with a CC (contabilista certificado) before filing. The distinction is genuinely ambiguous at the margins, and getting it wrong in either direction has consequences.

For the vast majority of translators, CIRS 1334 at 0.75 is the correct answer.

The tax mechanics for CIRS 1334 translators

The 0.75 coefficient. Under the simplified regime, 75% of your gross revenue is taxable. The remaining 25% is treated as assumed business costs. You don't need receipts for it, and you can't substitute actual expenses in its place even if your real costs, such as translation software licences, dictionaries, or continuing-education courses, were higher. Social Security contributions are separately deductible on top.

First-year discount. In your first calendar year of activity, only 37.5% of gross revenue is taxable, half the standard rate. In year two, 56.25%. This is based on the calendar year, not 12 months from your start date. Open your activity in March and you get nine months at the reduced rate; open it in October and you get two. To qualify: no employment or pension income in the same year, and no similar activity closed in the last five years.

Documented expense requirement. You still need to prove 15% of gross income in documented expenses: invoices with your NIF registered in the e-fatura system. An automatic specific deduction of roughly €4,587.09 (2026) counts toward this, or your Social Security contributions up to a cap of 10% of gross, whichever is larger. See the 15% expense rule fact page for the full mechanics.

Withholding from Portuguese clients. When a Portuguese entity pays you for translation or interpretation services, they are required to withhold 23% at source and pay it directly to AT. Since 1 January 2025, that has been the default rate (reduced from 25% by OE2025, Lei 45-A/2024, Art. 101 CIRS). You can opt up to the higher rate on the invoice if you prefer a larger advance against your annual IRS bill.

Withholding from foreign clients: nothing. When a London publisher pays you for a translation, all of it lands in your account. No tax has been sent to AT. The IRS liability is real; the mechanism that pre-pays it for Portuguese clients simply does not exist for foreign ones. If most of your income is foreign, build your own tax reserve. A rough working rule: set aside around a quarter of each foreign payment and reconcile at year-end filing.

The expat translator layer

Most guides covering CIRS 1334 are written for Portuguese translators with Portuguese clients. If you moved from the UK, Sweden, Germany, or the Netherlands and your publishers, agencies, and clients are back home or across Europe, those guides stop applying the moment you invoice your first foreign client.

Your old invoicing software is not legal here

Every platform used to issue legally valid Portuguese invoices must be certified by AT under Portaria 363/2010. Certified software assigns ATCUD codes to every document, communicates with AT systems, and generates the SAF-T audit file.

SDL Trados invoicing features, Word templates exported as PDF, FreshBooks, Xero, and similar tools are not AT-certified and cannot serve as your primary Portuguese invoicing system. This applies to CIRS 1334 translators and interpreters the same as everyone else. If you arrived with an existing invoicing setup from abroad, those invoices are not valid in the Portuguese tax system.

The free fallback is the AT portal itself (Portal das Financas, "Faturas e Recibos Verdes"), which is certified and costs nothing. For context on the certification landscape and what to look for in a third-party tool, see the expat freelancer tax automation guide.

Invoicing EU clients: 0% VAT, but not zero obligations

When you invoice a business client in another EU country, you issue at 0% VAT under Art. 6 CIVA. The place of supply is the customer's country; they reverse-charge in Germany, the Netherlands, or wherever they are. You use exemption code 115 on the invoice.

But 0% VAT is not the same as no VAT obligations. You must file the Declaracao Recapitulativa, a quarterly EU reporting document tracking intra-community B2B service transactions. It is required from your first EU invoice, regardless of whether you are on the Art. 53 domestic VAT exemption (the €15,000.00 threshold). Art. 53 covers what you charge Portuguese clients. It does not exempt you from cross-border reporting.

See the Art. 53 exemption glossary entry for the full scope.

Foreign SaaS subscriptions: reverse-charge from day one

Translation memory software, CAT tools, terminology databases, cloud storage. If these come from EU or US providers, you are the sujeito passivo for those acquisitions under Art. 2(1)(g) CIVA. You self-assess and file reverse-charge VAT on them through your Declaracao Periodica.

This obligation starts with the first foreign supplier invoice. Art. 53 status does not exempt you from it. Practical consequence: if you have only Portuguese clients and no foreign software subscriptions, you may have no Declaracao Periodica to file under Art. 53. The moment you subscribe to a foreign CAT tool or cloud platform, you have one.

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The compliance picture for a CIRS 1334 translator with foreign clients: AT-certified invoicing, 0% VAT on EU B2B invoices with Declaracao Recapitulativa filed quarterly, Declaracao Periodica for reverse-charge VAT on foreign software tools, no withholding from foreign payments so you are managing your own IRS provision, quarterly Social Security declarations. None of it is complicated once you know it exists.

If you want invoicing that handles the ATCUD and SAF-T requirements from the first document, Descodify is AT-certified. The free tier covers invoicing; Completo (19 euros per month) covers VAT, Social Security, and IRS preparation.

Start your first invoice at descodify.pt.

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