October tax calendar has started in Portugal: The first important deadline is October 6

October's tax calendar has started for freelancers and companies in Portugal. According to the 2026 official calendar of the Autoridade Tributária e Aduaneira, there are different deadlines throughout the month, from invoice notifications to IVA returns, from IRS and IRC obligations to Modelo 30.

However, not all of these obligations apply to all taxpayers.

The date and transaction vary depending on whether the individual is self-employed or a company, the IVA regime and the type of transactions made.

October 6: Notification of billing information

One of the first important dates of the month is October 6.

According to the EC's official 2026 calendar, the October date for the obligation that taxpayers within the scope of IRS, IRC and IVA must submit invoice information for the previous period or information that no invoices were issued in the relevant period is October 6.

This process is important for businesses and taxpayers who issue invoices within the scope of atividade aberta.

Depending on the certified invoicing software used, the transfer of information may be automatic or via software.

20 October: IVA and other significant liabilities

One of the busiest dates in October is October 20.

Submission of the periodic IVA declaration and necessary annexes for taxpayers in the monthly IVA regime in the EC calendar is among the transactions that must be completed by October 20.

The same date is also valid for the declaração recapitulativa transaction of taxpayers who have a monthly sending obligation. is available.

Additionally, some withholding and payment obligations under the IRS and IRC are also concentrated in this part of the month.

However, the point that should be particularly noted here is that not every freelancer is on the monthly IVA regime.

Different rules may apply for people covered by the three-month regime or IVA exemption.

Pay attention to the end of the month for Modelo 30

There is also a notification obligation in October for Modelo 30, which is used if certain income is paid or accrued to non-resident individuals or organizations in Portugal.

In the EC's official calendar, the relevant deadlines for these notifications are determined according to the payment period, and there are additional obligations to be followed at the end of October.

Modelo 30 may be especially important for Portuguese businesses and profissionais independentes that make payments to people or companies abroad.

However, not every payment made abroad is automatically covered by Modelo 30; The nature of the income and its tax status are decisive.

Not everyone who uses Recibos verdes has to do all these steps

The long list of obligations in the October tax calendar should not be assumed to apply to everyone using individuais or recibos verdes.

For example, the obligations of a trabalhador independente exempt from IVA under Article 53 of the Código do IVA are not the same as those of a company in the monthly IVA regime.

Similarly, IRS withholding The obligation to do so may also vary depending on the person's income, type of activity and the applicable tax regime.

For this reason, the presence of a transaction in the calendar does not mean that all taxpayers must submit that declaration.

What to do in October?

The safest method for individuals and companies with atividade aberta is to check the personal tax situation and the accounting regime used on the Portal das Finanças.

In businesses operating with a contabilista certificate, most of the obligations are followed by the accountant.

Trabalhadores independentes, who manage their own transactions, can reduce the risk of delay by checking invoice notification, IVA regime and withholding tax obligations, if any, at the beginning of the month.

The first important date in terms of the official calendar is October 6; The second critical point of the month is October 20.

Resources

Autoridade Tributária e Aduaneira — Resumo anual: Obrigações declarativas em 2026

https://info.portaldasfinancas.gov.pt/pt/apoio_contribuinte/calendario_fiscal/Pages/Quadro_res_Decl_2026.aspx

ECO — Das retenções na fonte de IRS e IRC ao IVA. Veja as obrigações fiscais de outubro, 1 October 2026

https://eco.sapo.pt/2026/10/01/das-retencoes-na-fonte-de-irs-e-irc-ao-iva-veja-as-obrigacoes-fiscais-de-outubro/