How to Prepare Your IRS?

Personal Income Tax (IRS) is not limited to filling in an electronic form.

Between 1 April and 30 June, taxpayers submit the Modelo 3 return through the Finance Portal (Portal das Finanças). However, the relevant moment is not the submission itself. The decisive moment is the preparation.

IRS constitutes an annual tax assessment exercise that involves:

• Legal qualification of income;

• Correct identification of the household;

• Verification of tax deductions;

• Consideration of alternative regimes (aggregation or autonomous taxation);

• Choice between joint or separate taxation.

IRS is therefore a strategic decision — a true annual financial diagnosis. In many cases, it represents the difference between paying more tax or recovering hundreds or even thousands of euros that are rightfully yours.

When Does IRS Begin?

One of the most frequent misconceptions is associating IRS solely with the filing period.

In reality, the process begins months earlier, namely when the taxpayer:

• Validates the household composition by 2 March;

• Confirms and correctly classifies invoices on e-Fatura or the Finance Portal by 2 March;

• Decides whether aggregating income is advantageous;

• Simulates joint versus separate taxation.

A well-prepared IRS return is not merely completed — it is structured.

Household: A Detail That Can Be Costly

The composition of the household is a central element in determining the tax due.

Changes such as:

• Marriage or de facto union;

• Divorce or separation;

• Birth of children;

• Loss of dependent status,

have a direct impact on tax rates, deduction limits, and the final tax assessment.

The deadline to update your household is 2 March.

This update is not a mere administrative formality. It is a critical point of tax optimisation. A simple error at this stage may result in the loss of deductions throughout the entire year.

Invoices with Tax Identification Number (NIF): The Line Between Consumption and Strategy

Without a Tax Identification Number (NIF), a transaction is merely consumption and remains irrelevant for deduction purposes.

With a NIF, it becomes part of your tax organisation. The issuance of an invoice including the taxpayer’s fiscal identification is an essential condition for the expense to be recognised by the Tax and Customs Authority.

Requesting an invoice with your NIF is effectively building your own tax-saving mechanism. If IRS were a game, invoices with a NIF would be your tokens.

Invoice Validation: A Small Action Worth Hundreds (or Thousands) of Euros

Until 2 March, taxpayers must confirm and classify the expenses recorded on e-Fatura.

Most entries are automatic, but they are not always correct. This is an act of fiscal qualification, as the proper allocation of each expense to the relevant category determines its relevance for tax assessment.

It is therefore essential to understand the main deduction categories.

1. General Family Expenses

An amount corresponding to 35% of the expenditure borne by any member of the household is deductible from the tax due, up to a global limit of €250.00 per taxable person.

Examples include supermarket purchases, clothing, laundries, perfumeries, household appliances, consoles, furniture and decoration, fuel, water, electricity, gas, and telecommunications services (television, internet, mobile and landline services).

2. Health Expenses

15% of health expenses borne by the household are deductible, up to a global limit of €1,000.00.

These include:

• Medical consultations, examinations or hospitalisation;

• Health insurance premiums;

• User fees for consultations or other clinical services;

• Costs with ophthalmologists, optometrists and orthoptists, including ophthalmic lenses, crutches, dentures or dental correction devices. Eyeglass frames are only accepted as health expenses if accompanied by a medical prescription;

• All medicines purchased in pharmacies, para-pharmacies or supermarkets, provided that they are:

a) VAT-exempt or subject to the reduced VAT rate (6%) — these expenses are directly deductible;
b) Subject to the standard VAT rate (23%) — in such cases, the expenses remain in “pending” status until associated with a medical prescription to justify the expense.

3. Education and Training Expenses

30% of education and training expenses, including vocational training, incurred by any member of the household are deductible, up to a global limit of €800.00.

This category includes:

• Nurseries, kindergartens, after-school activities, childminders and educational establishments;

• Extracurricular activities (language, music, singing, theatre lessons, among others);

• Private tutoring and vocational training;

• School textbooks and manuals;

• Meals provided at school cafeterias;

• Rent for rooms or property paid by displaced students.

4. Property-Related Expenses

Tenants may deduct 15% of rent paid for residential purposes, within the applicable legal limits.

Landlords may declare certain expenses incurred in relation to rented property.

Deductible property expenses include:

• Condominium fees;

• Municipal Property Tax (IMI);

• Stamp Duty and municipal charges;

• Insurance premiums;

• Maintenance and repair costs (electrical or plumbing repairs, interior and exterior painting);

• Shared service charges (concierge services, cleaning, security, lifts, lighting and climate control).

5. Nursing Home Expenses

25% of expenses related to nursing homes and home support services are deductible, up to a global limit of €403.75.

6. Expenses in Specific Sectors of Activity

Certain expenses allow deductions based on the VAT borne.

a) Sectors with 15% VAT Deduction (global limit of €250.00)

An amount corresponding to 15% of the VAT borne by any member of the household is deductible, up to a global annual limit of €250.00 per household, in relation to:

• Motor vehicle maintenance and repair;

• Motorcycle maintenance and repair, parts and accessories;

• Accommodation, catering and similar services;

• Hairdressing and beauty institutes;

• Veterinary activities.

b) Sectors with Enhanced Deduction

Different percentages apply depending on the nature of the activity:

• Gym activities (fitness, sports clubs, sports and recreational education): deduction corresponding to 30% of the VAT borne;

• Purchase of monthly passes or tickets for public collective transport: deduction corresponding to 100% of the VAT borne;

• Subscriptions to periodical publications (newspapers and magazines), including digital editions, subject to the reduced VAT rate: deduction corresponding to 100% of the VAT borne.

All these deductions are subject to the global annual limit of €250.00 per household.

c) Domestic Work

In the case of domestic work, the regime differs as to the taxable base: 5% of expenses borne by the household are deductible, up to a global limit of €200.00.

Pending Invoices

The classification of an invoice as “pending” does not indicate any irregularity, but rather insufficient fiscal information regarding the specific nature of the expense.

This frequently occurs when the issuing entity carries out multiple economic activities registered under different activity codes — a common reality in large retail establishments.

The Tax and Customs Authority receives information concerning the identity of the invoice issuer, but not the specific goods or services acquired by the consumer. The tax system knows who issued the invoice; it does not know the material content of the transaction.

Accordingly, the taxpayer bears the burden of properly allocating the expense to the relevant fiscal category.

Without this express validation, the system cannot determine the correct legal and tax classification of the expense, and it may therefore not be considered for deduction purposes.

In substantive terms, this is an act of fiscal qualification that directly affects the amount of tax to be assessed. Validating pending invoices thus represents an active intervention by the taxpayer in shaping their own tax outcome.

A reflexion

IRS is not merely a form to be completed. It is an annual moment of strategic financial analysis.

You may choose to treat it as a bureaucratic obligation. Or you may transform it into a powerful tool for tax optimisation — capable of maximising deductions and rationalising income.

Ultimately, mastering IRS is not only about complying with the law — it is about planning, protecting and enhancing your assets. And that is the difference between paying more than you should or recovering what is legitimately yours.

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