The IRS is expected to begin the 2026 tax season by accepting e-filed returns on or around Monday, January 26, 2026. The general deadline for filing 2025 federal income tax returns and paying any tax owed is April 15, 2026.

The Internal Revenue Service encourages taxpayers to take steps now to prepare for the upcoming filing season. A little advanced work preparing paperwork and organizing information now can help with filing tax returns quickly and accurately.

It is important for taxpayers to get ready now because the One, Big, Beautiful Bill can significantly affect federal taxes, credits and deductions. The IRS and Treasury are working to implement the new legislation, including providing information on the new tax deductions, such as no tax on tips, no tax on overtime, no tax on car loan interest, the new temporary deduction for seniors and others.

Gather and organize tax records.

Having organized tax records helps taxpayers file complete and accurate tax returns and avoid errors that could delay refunds. Start by collecting:

• US Bank account information.
• Forms W-2 from your employer(s).
• Forms 1099 from banks and other payers.
• Records of digital asset transactions.

Taxpayers should wait to file until they have received all their tax records, so if you need to file the Spanish Tax Return (IRPF) or the Portuguese’s IRS3, you need to wait until the first week of April. The Spanish residents need the “datos fiscales” from the AEAT, which are required to prepare you US Tax return, just in case we ask the IRS for an extension to file for all our clients until October 15^th.

Online Account

An IRS online account allows taxpayers to access personal tax information, including recently filed returns, securely. Through this tool, taxpayers can:

• View tax records, including adjusted gross income and transcripts.

• Make, schedule and view payments.
• Get or view their Identity Protection PIN (IP PIN).
• Authorize US tax Consultants to access your tax records digitally.
• Access available Forms W-2 and certain 1099s.

Speed tax refunds with direct deposit! Direct deposit is the fastest way to receive a refund. Additionally, in accordance with Executive Order 14247, the IRS began phasing out paper tax refund checks on Sept. 30, 2025, which means most taxpayers must provide routing and account numbers to get their refunds directly deposited into their bank accounts.

Key Dates for the 2026 US Tax Season

• IRS e-filing opens: Expected to be in the last week of January, with current estimates targeting January 26, 2026.
• Tax Day: April 15, 2026, is the deadline to file returns for the 2025 tax year and pay any taxes owed. Remember that if you live abroad your filing deadline is June 15th.
• Extended deadline: Taxpayers can file Form 4868 to get an automatic extension to file until October 15, 2026, though payment of taxes owed is still due by April 15. US Tax Consultants files Form 4868 for all our clients.
• Refunds for EITC/ACTC filers: By law, refunds for those claiming the Earned Income Tax Credit (EITC) or Additional Child Tax Credit (ACTC) are delayed until mid-February, with a target availability date of early March 2026 for most direct deposits. 

Important Changes for 2026 U.S. Taxation

• Direct Deposit Only: The IRS will no longer issue paper refund checks; all refunds must be received via direct deposit. Taxpayers without a traditional bank account can use a prepaid debit card that provides account and routing numbers.
• New Deductions/Credits: Changes from the “One Big Beautiful Bill Act” passed in July 2025 introduce new tax deductions, such as no tax on tips and overtime for certain workers, and an increased state and local tax (SALT) deduction for eligible homeowners.
• Higher Standard Deduction: The standard deduction amounts have increased for all filing statuses due to inflation adjustments and new legislation.
• Refund Status: The IRS advises using the “Where’s My Refund?” tool on the IRS website or the IRS2Go app to track refund status, which is typically updated within 24 hours of the IRS accepting an e-filed return. 

Recommendations for Taxpayers

• Gather documents early: Collect all necessary documents, such as W-2 and 1099 forms, as soon as possible. These should be mailed by employers and financial institutions by January 31, 2026. If you file IRPF in Spain, please, be sure that you have a bank account in a valid AEAT bank institution and you NIF up to date.
• File electronically and use direct deposit: This is the fastest way to receive any refund owed, with most refunds issued within 21 days of acceptance (barring delays).
• File early to prevent identity theft: Filing an accurate return early can reduce the chance of identity thieves filing a fraudulent return in your name. 

Deadlines for the Spanish IRPF, the Portuguese IRS3 and the U.S. Form 1040

Understanding the timing requirements of both the Spanish Personal Income Tax (IRPF – Modelo 100)/ Portuguese IRS3 and the U.S. Individual Income Tax Return (Form 1040) is essential for dual filers, tax residents abroad, and U.S. citizens living in Spain or Portugal. Though both systems run on the calendar‑year tax period, their filing windows, payment deadlines, and extension rules differ substantially.

1. Spanish IRPF (Modelo 100): Filing Deadlines and Key Date Implications

Spain’s IRPF is filed annually for the prior tax year, covering income earned from 1 January to 31 December. Online filing begins during the first week of April 2026 and the deadline will be June 30. It is the absolute final deadline for filing the IRPF return.

If the return results in tax due and the taxpayer pays by direct debit, the deadline to request the direct debit is June 25. The payments will then be charged to your bank account on June 30 (60%) and November 5 (40%).

A few reminders:

• Spain does not provide formal extensions for IRPF filing comparable to the U.S. Form 4868.
• Filing late typically triggers surcharges and interest automatically.
• Payment method materially affects deadlines (direct debit vs. manual payment).

2. Portuguese IRS3: Filing Deadlines and Key Date Implications

Main Filing Window (IRS / Modelo 3): The annual Portuguese personal income tax return for income earned in 2025 must be filed: 1 April 2026 to 30 June 2026.

This filing window applies to all taxpayers, including residents and non‑residents who must declare Portugal‑sourced income.

Payment Deadline for IRS3 Tax Due, if the final IRS assessment results in tax payable is due by 31 August 2025.

Extensions (IRS Model 49) – Only in special cases: Taxpayers who have foreign‑sourced income and cannot determine foreign‑tax credits on time may request a deadline extension via Modelo 49 until 31 December 2026.

3. Comparative Analysis: IRPF/IRS3 vs. Form 1040 Filing Dates

Category	Spain – IRPF (Modelo 100)	U.S. – Form 1040	Portugal – IRS (Modelo 3)
Tax Year Covered	2025 income	2025 income	2025 income
Main Filing Window	First week Apr – 30 Jun 2026	26 Jan – 15 Apr 2026	1 Apr – 30 Jun 2026
Final Filing Deadline	30 Jun 2026	15 Apr 2025 (or 15 Oct with extension)	30 Jun 2025
Direct‑Debit Payment Deadline	25 Jun 2025 (tax‑due with direct debit)	N/A	N/A
Payment Collection Dates	60% on 30 Jun & 40% on 5 Nov (AEAT schedule for split payments)	Full payment due 15 Apr 2025, unless approved for IRS installment plan	31 Aug 2025 for IRS payment after assessment
Extension Available?	No general extension	Yes — Form 4868 → 15 Oct 2025 (payment still due 15 Apr)	Yes — Modelo 49 (in specific cases of foreign income) → 31 Dec 2025
Special Rules for Taxpayers Abroad	N/A	Automatic extension to 15 Jun for U.S. citizens abroad (interest from 15 Apr)	N/A
Quarterly Estimated Payments	Applies only to autonomous through separate filings.	15 Apr, 17 Jun, 15 Sep 2025 & 15 Jan 2026	Not applicable for IRS (Modelo 3) Only VAT & self‑employed regimes have separate obligations

4. Practical Implications for Dual Filers (U.S. Citizens in Spain and or Portugal)

Mismatched deadlines require careful coordination: Spanish and Portuguese filing ends 30 June, while the U.S. requires filing (or paying) by 15 April. Many expatriate taxpayers benefit from the automatic 15 June U.S. extension, but interest still begins on 15 April.

Foreign Tax Credit (FTC) timing considerations: Because Spanish and Portuguese taxes may not be fully paid until late June, U.S. taxpayers often require the 15 October extension to properly calculate foreign tax credits.

Foreign Earned Income Exclusion (FEIE): Filing extensions do not affect FEIE eligibility based on physical presence or bona fide residence, but accurate coordination of dates helps avoid amended returns.

Cash‑flow planning: Spain’s and Portuguese’s later deadlines may create liquidity challenges if taxpayers owe both Spanish/Portuguese and U.S. tax within a short window.

Conclusion

Filing the Spanish IRPF and the U.S. Form 1040 involves navigating two distinct systems with different filing windows, payment deadlines, and extension rules. Spain grants a broad window from early April to 30 June, while the U.S. anchors everything around 15 April, with structured extensions and quarterly payment rules. For taxpayers with obligations in both countries – especially U.S. citizens residing in Spain and Portugal – aligning these timelines is essential to avoid penalties, optimize foreign tax credits, and ensure compliance with both tax authorities.

If you still have any questions or concerns regarding the filing deadlines for tax returns in Spain, Portugal, or the United States, please feel free to contact us at +34 915 194 392 or book a free, no‑obligation consultation through our online scheduling service. We’ll be happy to guide you through the process and provide the clarity you need.

Antonio Rodriguez – US Tax Consultants