Month-by-month 2026 tax calendar.
January
- Self-employed quarterly declaration for Q4 prior year Segurança Social Direta
- IFICI inscription deadline, 15 January AT IFICI FAQ
- United Kingdom: Self Assessment online deadline, 31 January HMRC
February
- Household composition update, 15 February Portal das Finanças
- e-Fatura validation deadline, 25 February Portal das Finanças
- Germany: advisor-extended prior-year filing often falls in February Bundesfinanzministerium
March
- Pre-filing checks: residency, regime status, Anexo J evidence Modelo 3 guidance
- South Africa: provisional-tax follow-up dates vary by SARS annual notice SARS
April
- Modelo 3 IRS filing window opens, 1 April Portal das Finanças
- Self-employed quarterly declaration for Q1 Segurança Social Direta
May
- First IMI installment where assessment exceeds €100 Portal das Finanças IMI
- Modelo 22 corporate IRC filing window Portal das Finanças
- Canada: self-employed balance due remains 30 April, filing can run later CRA
June
- Modelo 3 IRS filing window closes, 30 June Portal das Finanças
- IES deadline for businesses Portal das Finanças
- United States: automatic expat extension for Form 1040, 15 June IRS
July
- Self-employed quarterly declaration for Q2 Segurança Social Direta
- Germany: Einkommensteuer standard filing deadline, 31 July Bundesfinanzministerium
August
- Second IMI installment where total assessment exceeds €500 Portal das Finanças IMI
- South Africa: first provisional taxpayer payment commonly due around 31 August SARS
September
- AIMI payment Portal das Finanças IMI
- Canada: instalment deadline where CRA instalments apply CRA
October
- Self-employed quarterly declaration for Q3 Segurança Social Direta
November
- Third IMI installment where applicable Portal das Finanças IMI
- South Africa: annual return dates vary by SARS filing-season notice SARS
December
- Year-end residency, disposal, and next-year State Budget review Portal das Finanças
About Taxbordr: founder-led tax calendar coordination
Taxbordr is a Lisbon-based cross-border tax advisory founded by Telmo Ramos, member of the Ordem dos Economistas, Cédula nº 16379. Telmo trained at KPMG Luxembourg and EY Lisbon. He founded Taxbordr in 2022. The firm has handled 250+ cross-border cases, including dual-deadline coordination across the Portuguese Modelo 3 cycle and the US 1040, UK self-assessment, German Steuererklärung, Canadian T1, and South African ITR12 cycles. The calendar below is what we work to internally; we maintain a client-specific deadline file for each engagement.
Month-by-month 2026 tax calendar (Portuguese deadlines)
January 2026 - 10-20 Jan: Self-employed monthly SS contribution (Dec 2025 base) - 15 Jan: IFICI application deadline for prior-year residency (CIRS art 81 n.º 4 election; Portaria 352/2024/1) - 31 Jan: Q4 2025 self-employed SS Income Declaration on Segurança Social Direta - 31 Jan: IES (Informação Empresarial Simplificada) deadline if not aligned to Modelo 22 cycle for individual filers
February 2026 - 10-20 Feb: Self-employed monthly SS contribution (Jan 2026 base) - 15 Feb: First month of IRS regularization filings for prior-year corrections under CIRS art 59
March 2026 - 10-20 Mar: Self-employed monthly SS contribution (Feb 2026 base) - 31 Mar: Modelo 22 (corporate IRS) deadline for entities with calendar-year fiscal year (CIRC art 117). Note: companies pay first PEC instalment in March
April 2026 - 1 April: Modelo 3 IRS filing window opens (for 2025 income tax year) - 10-20 Apr: Self-employed monthly SS contribution (Mar 2026 base) - 30 Apr: Q1 2026 self-employed SS Income Declaration on Segurança Social Direta - 30 Apr: First IUC (Imposto Único de Circulação) annual payment for vehicles registered Apr-2025
May 2026 - 10-20 May: Self-employed monthly SS contribution (Apr 2026 base) - 31 May: First IMI installment (single payment if total ≤ €100; first of two if €100 < total ≤ €500; first of three if total > €500) - 31 May: PEC (Pagamento Especial por Conta) for Modelo 22 corporate filers
June 2026 - 10-20 Jun: Self-employed monthly SS contribution (May 2026 base) - 30 June: Modelo 3 IRS filing deadline (for 2025 income tax year). Filing extensions are exceptional and must be formally requested.
July 2026 - 10-20 Jul: Self-employed monthly SS contribution (Jun 2026 base) - 15 July: IES deadline (Informação Empresarial Simplificada, annual for entities with calendar fiscal year) - 31 Jul: Q2 2026 self-employed SS Income Declaration - 31 Jul: IMI second installment if applicable
August 2026 - 10-20 Aug: Self-employed monthly SS contribution (Jul 2026 base) - 31 Aug: Modelo 3 settlement payment due date (where IRS apuramento shows tax owed) - 31 Aug: IMI second installment for two-installment plan; second of three for three-installment plan
September 2026 - 10-20 Sep: Self-employed monthly SS contribution (Aug 2026 base) - 30 Sep: AIMI annual payment (single payment, no installment plan) - 30 Sep: PEC second installment for Modelo 22 filers
October 2026 - 10-20 Oct: Self-employed monthly SS contribution (Sep 2026 base) - 31 Oct: Q3 2026 self-employed SS Income Declaration
November 2026 - 10-20 Nov: Self-employed monthly SS contribution (Oct 2026 base) - 30 Nov: IMI third installment for three-installment plan; second installment for two-installment plan
December 2026 - 10-20 Dec: Self-employed monthly SS contribution (Nov 2026 base) - 15 Dec: PEC third installment for Modelo 22 filers - 31 Dec: Final cut-off for residency-establishing acts that affect 2026 Cat A/B/E/F/G/H allocation
IVA (VAT) quarterly returns
Standard taxpayers (annual turnover < €650,000) file IVA returns quarterly:
Q4 2025 IVA: due 15 Feb 2026 (or 20 Feb on calendar adjustments)
Q1 2026 IVA: due 15 May 2026
Q2 2026 IVA: due 15 Aug 2026
Q3 2026 IVA: due 15 Nov 2026
Monthly IVA filers (turnover ≥ €650,000): the 10th of the second month following the period (e.g. Jan 2026 IVA due 10 Mar 2026). Reverse-charge invoicing for EU clients with VIES registration affects the form, not the due date.
United Kingdom (HMRC) parallel deadlines
31 January 2026: Self-Assessment online filing deadline for 2024/25 tax year + balancing payment + first payment on account 2025/26
5 April 2026: UK 2025/26 tax year ends
6 April 2026: UK 2026/27 tax year begins; new UK-PT DTC effective date for UK Income/CGT
31 July 2026: Second payment on account 2025/26
31 October 2026: Self-Assessment paper filing deadline for 2025/26 (online has a later deadline)
United States (IRS / FinCEN) parallel deadlines
15 April 2026: Form 1040 deadline (US tax year is calendar year)
15 June 2026: Automatic 2-month extension deadline for US persons abroad (filing only; payment was due 15 April)
15 October 2026: Form 1040 with Form 4868 extension (final deadline)
15 April 2026: FBAR (FinCEN 114) original deadline; 15 October 2026: automatic FBAR extension
15 April 2026: Form 8938 (FATCA) statement attached to Form 1040
31 December 2026: US tax year ends
Form 1099-DA broker reporting deadlines (effective 1 Jan 2025; basis reporting from 2026) follow the underlying broker's normal 1099 cycle
Germany (Bundesfinanzministerium / Finanzamt) parallel deadlines
31 July 2026: Einkommensteuer (income tax) filing deadline for 2025 tax year (mandatory filers, no Steuerberater)
End of February 2027: Filing deadline for 2025 tax year if represented by Steuerberater (extended deadline)
Quarterly Einkommensteuer-Vorauszahlungen: 10 March, 10 June, 10 September, 10 December
Anmeldung obligations on relocation: complete with Bürgeramt before residency change
Canada (CRA) parallel deadlines
30 April 2026: T1 personal tax return filing deadline + balance due (for 2025 tax year)
15 June 2026: Self-employed T1 filing deadline (balance still due 30 April)
30 April 2026: First instalment of 2026 if required; subsequent on 15 Jun, 15 Sep, 15 Dec
31 December 2026: Canadian tax year ends
South Africa (SARS) parallel deadlines
20 January 2026: Provisional taxpayer second period payment for 2025/26 year of assessment
End of February 2026: SARS year of assessment ends
August / October 2026 (per SARS announcement): ITR12 filing season opens
SARB exchange-control filings (RAV01) due on cessation of tax residency event
General rules
Where a deadline falls on a weekend or a Portuguese public holiday, the deadline shifts to the next business day per LGT
Late filing triggers automatic juros de mora (LGT art 35) plus a coima under RGIT
Modelo 3 amendments (substituição) are permitted within prescribed windows under CIRS art 59 / art 60; voluntary substitution before AT inspection generally limits the coima
Frequently Asked Questions
When is the Portugal IRS deadline 2026?
The Modelo 3 filing window for 2025 income runs from 1 April 2026 to 30 June 2026. Settlement payment (where tax is owed) is generally due by 31 August 2026. Late filing triggers juros de mora and a coima under RGIT.
When is the IFICI application deadline?
15 January of the year following the residency year, per Portaria 352/2024/1. Late applications are not accepted; the IFICI election is forfeited for that year. Coordination of the residency start date with the application window is a planning lever for clients moving in late Q4.
What is the IMI payment schedule in 2026?
Total IMI ≤ €100: single payment in May. €100 < total ≤ €500: two installments in May and November. Total > €500: three installments in May, August, and November. AIMI is a separate annual payment, due in September.
When is IES due in Portugal in 2026?
15 July 2026 for entities with a calendar fiscal year. IES (Informação Empresarial Simplificada) is the annual statistical and accounting filing combining several declarations to AT, INE, BdP, and Ministério da Justiça.
When are quarterly self-employed SS declarations due?
January (Q4 prior year), April (Q1), July (Q2), October (Q3). The declaration sets the contribution base for the following quarter (70% of services turnover; 20% of goods turnover). Monthly contributions are paid the 10th to 20th of the following month.
What is the deadline for US persons filing from Portugal?
Form 1040: 15 April 2026 (payment); 15 June 2026 (automatic extension for filing only, with US persons abroad); 15 October 2026 (final extension with Form 4868). FBAR: 15 April 2026 with automatic extension to 15 October 2026.