CIRS

CIRS is the legislation. IRS is the tax. When a freelancer in Portugal says they "pay IRS," they mean the tax defined by the Codigo do Imposto sobre o Rendimento das Pessoas Singulares.

For most freelancers, the practical entry point into CIRS is Article 151, which is where the activity codes that classify your work live.

CIRS vs CAE: two different systems

This distinction causes more confusion than almost anything else in Portuguese freelancer registration.

CIRS is maintained by AT (Autoridade Tributaria e Aduaneira), the tax authority. It governs individual income. When you open your activity as a trabalhador independente (independent worker) at the Portal das Financas, you register under a code from the Art. 151 CIRS table.

CAE (Classificacao Portuguesa de Atividades Economicas) is maintained by INE (Instituto Nacional de Estatistica), the national statistics office. It classifies economic entities: companies, branches, establishments. When a Lda forms, it picks a CAE.

You are an individual. You use a CIRS code. A company uses a CAE code. The same number can appear in both systems but refers to different things: CIRS 1332 is the code for individual programmer-freelancers; CAE 62010 is the code for programming companies.

See the CAE glossary entry for the full side-by-side comparison.

What Art. 151 governs

Article 151 of CIRS does one thing: it lists professional activities and assigns each one a code. That code determines your simplified-regime (regime simplificado) coefficient, which is the multiplier AT applies to your gross revenue to calculate taxable income.

Named professions in the Art. 151 table carry the 0.75 coefficient: 75% of gross revenue is taxable, 25% is treated as assumed business costs. This applies to programmers (code 1332), consultants (1320), architects, engineers, lawyers, accountants, doctors, and most other listed professions.

The catch-all code for activities not specifically named is code 1519 ("outros prestadores de servicos," other service providers). Its coefficient is 0.35: only 35% of gross revenue is taxable. In raw numbers it looks more favorable, but using it when a specific code applies to your activity is a misclassification.

Common Art. 151 codes for tech and creative freelancers

Code	Activity (PT)	Activity (EN)	Coefficient
1332	Programadores informaticos	Programmers	0.75
1313	Analistas de sistemas	Systems analysts	0.75
1320	Consultores	Consultants	0.75
1336	Designers	Designers	0.75
1519	Outros prestadores de servicos	Other service providers	0.35

For a full breakdown of how CIRS 1332 specifically works for programmer-freelancers in Portugal, including the expat-specific cross-border obligations, see CAE vs CIRS: what activity code do you actually need as a programmer?

The coefficient and what it means

Under the simplified regime, AT doesn't ask you to prove your expenses item by item. Instead, it assumes a fixed percentage of your gross revenue went to business costs and taxes you on the rest.

For a programmer on code 1332, earn €40,000 in a year and AT taxes you on €30,000 (75%). The other €10,000 is the assumed expense deduction. Social Security contributions are separately deductible on top.

You still need to prove 15% of gross income in documented expenses (invoices with your NIF in the e-fatura system), but an automatic specific deduction of roughly €4,587.09 (2026) counts toward that threshold, or your Social Security contributions up to a cap of 10% of your gross, whichever is larger. At income under roughly €30,580, you may not need to show any additional expenses. Foreign supplier invoices (Stripe, AWS, and similar) don't appear in e-Fatura automatically but still count if you register them manually on the e-Fatura portal (registar fatura as adquirente) or declare them in Anexo B Quadro 17, keeping originals 10 years (Art. 52 CIVA).

See regime simplificado for the full mechanics including first-year discounts and the organized-accounting threshold.

CIRS vs CIRC

CIRS governs personal income tax (individuals). CIRC (Codigo do Imposto sobre o Rendimento das Pessoas Coletivas) governs corporate income tax (companies). If you operate as a sole proprietor, CIRS applies. If you form a Lda or Unipessoal Lda, CIRC applies to the company and CIRS applies to income you extract from it (salary, dividends).

The two codes have separate simplified regimes, separate coefficients, and separate rate tables. Running a company and running a sole proprietorship are not the same tax situation, even when the underlying commercial activity is identical.