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ITIN Renewal application reference for Substack writers based in Denmark
ITIN15 min read

An ITIN Renewal Guide for Substack writers from Denmark

Substack writers in Denmark need to renew their ITIN for US tax compliance. This guide covers eligibility, required documents, the process, and common pitfalls.

Reviewed by , ITIN Specialist at itin.net.

Why Substack Writers in Denmark Need to Renew Their ITIN

As a Substack writer based in Denmark, you likely receive payments from U.S.-based platforms like Substack itself or through payment processors such as Stripe. These platforms are often required by the IRS to report payments made to non-U.S. persons. To ensure accurate tax reporting and avoid backup withholding, you need a U.S. taxpayer identification number, typically an Individual Taxpayer Identification Number (ITIN) if you don't qualify for an Employer Identification Number (EIN).

Your existing ITIN may require renewal if it has expired. The IRS uses a rolling expiration schedule based on the middle digits of the ITIN, and any ITIN not used on a federal tax return for three consecutive years is also invalidated. For Danish residents earning income from U.S. sources via platforms like Substack, maintaining a valid ITIN is crucial for compliance with U.S. tax regulations, especially given the U.S. Denmark tax treaty. Failure to renew can lead to significant tax complications and potential penalties.

When ITIN Renewal Becomes Necessary

Your ITIN requires renewal under specific circumstances, primarily dictated by IRS policy. The most common trigger is the IRS's scheduled expiration of ITINs. This expiration is based on the middle two digits of your ITIN and occurs on a rolling basis. For example, ITINs ending in '70' and '80' expired in 2021, followed by '90' and '00' in 2022. You can check the current IRS schedule to see if your ITIN falls within an affected group.

Additionally, an ITIN is automatically invalidated if you do not use it on a U.S. federal tax return for three consecutive tax years. If you have been receiving payments from U.S. platforms like Substack and haven't filed a U.S. tax return using your ITIN in the last three years, it is likely expired. The IRS may send a notice, such as CP-48, indicating your ITIN is invalid, but you should not rely solely on receiving this notice. Proactively checking your ITIN status is a more reliable approach to ensure continuous compliance.

Essential Documents for ITIN Renewal

To renew your ITIN, you will need to submit Form W-7, Application for IRS Individual Taxpayer Identification Number, to the IRS. Ensure you check the box indicating you are renewing an existing ITIN. Along with the completed W-7, you must provide original or certified copies of documentation proving your identity and foreign status. The primary document required is your valid passport.

If your passport has expired, you can use other acceptable identification documents, but a passport is generally the most straightforward option. You may also need to provide your previous ITIN notice (if available) or any IRS correspondence related to your ITIN. Critically, you must include a valid U.S. federal tax return with your Form W-7 application. This tax return demonstrates why you need the ITIN. For Substack writers in Denmark, this would typically be a Form 1040-NR, U.S. Nonresident Alien Income Tax Return, reporting the income received from your newsletter.

The ITIN Renewal Process Step-by-Step

The process for renewing your ITIN involves several key steps. First, you must complete Form W-7, Application for IRS Individual Taxpayer Identification Number, ensuring you select the option for ITIN renewal. You will then need to prepare your U.S. federal tax return, typically Form 1040-NR, which you will file along with the W-7. Gather your supporting identification documents, primarily your valid passport, and any other required documentation proving your identity and foreign status.

Once your application package is complete, you have two main options for submission. You can mail the entire package directly to the IRS ITIN Operation in Austin, Texas. Alternatively, you can apply through a Certified Acceptance Agent (CAA), such as itin.net. Using a CAA can expedite the process because they can verify your original documents, returning them to you immediately without you having to mail them to the IRS. The IRS typically processes ITIN renewals within 5–10 business days through a CAA, though direct mail applications can take longer. Once approved, you will receive a new ITIN notice from the IRS.

Common Mistakes for Substack Writers in Denmark

Substack writers in Denmark renewing their ITIN often encounter specific issues related to their cross-border income and filing status. One common pitfall is failing to correctly report income received via Stripe or other U.S. payment processors on their Form 1040-NR. Ensuring all income streams are accounted for is essential for a complete tax return. Another mistake is submitting incomplete or incorrect identification documents. Mismatched names between your Form W-7, your passport, and any previous IRS correspondence can cause delays or rejection.

Many Danish writers may overlook the requirement to file a tax return with their W-7 application. The ITIN is issued to facilitate U.S. tax reporting, so the IRS needs to see that you are fulfilling this obligation. Relying solely on receiving an IRS notice like CP-48 to prompt renewal is also a mistake; proactive checking is far more effective. Finally, confusion can arise regarding treaty benefits; while Denmark has a tax treaty with the U.S., claiming these benefits requires proper documentation and adherence to specific IRS procedures on your tax return.

Benefits of Using a Certified Acceptance Agent (CAA)

Applying for ITIN renewal through a Certified Acceptance Agent (CAA), like itin.net, offers distinct advantages for Substack writers in Denmark. The most significant benefit is the verification of your original identification documents. Instead of mailing your valuable passport and other original documents to the IRS, you can present them to a CAA. The CAA will then review and certify copies of these documents, returning your originals to you on the spot. This significantly reduces the risk of loss or delay associated with mailing sensitive documents.

Furthermore, CAAs are trained to assist with the ITIN application process, helping to ensure that your Form W-7 and supporting documentation are correctly completed and submitted. This can help prevent common errors that lead to application rejections. The typical processing time for ITIN renewals submitted via a CAA is often faster, usually within 5–10 business days, compared to mailing directly to the IRS, which can take considerably longer. This efficiency is particularly valuable when you need your ITIN for timely tax filing or other financial obligations.

Next Steps After ITIN Renewal

Once your ITIN renewal is approved by the IRS, you will receive an official ITIN Assignment Letter. This letter contains your new ITIN, which you must use for all future U.S. federal tax filings. For Substack writers in Denmark, this means updating your tax information with Substack and any other U.S. payment processors to include your renewed ITIN. This ensures accurate reporting of your income to the IRS and prevents issues like backup withholding.

It is advisable to keep your ITIN Assignment Letter and a copy of your renewed ITIN on file with your important tax documents. Remember that your ITIN needs to be used on a federal tax return at least once every three years to remain valid. Consider reviewing the itin.net Renewal Package pricing to understand the costs associated with expedited service or consulting with a tax professional to ensure ongoing compliance. If you have further questions, contacting itin.net directly can provide personalized assistance.

Practical tips

  • Use the exact same legal name on your Form W-7 as it appears on your passport and any other identification documents to avoid discrepancies.
  • Ensure your submitted U.S. federal tax return (e.g., Form 1040-NR) is complete and accurate before submitting it with your Form W-7 for renewal.
  • If you have an old ITIN notice or previous IRS correspondence, include it with your renewal application as it can help the IRS locate your existing record.
  • Check your ITIN status proactively on the IRS website or through a Certified Acceptance Agent, rather than waiting for an IRS notice like CP-48.
  • Confirm that your Danish passport is valid and has not expired; an expired passport is not acceptable for proving identity and foreign status.

Frequently asked questions

As a Substack writer in Denmark, do I need an ITIN if I'm not a U.S. resident?

Yes, if you are receiving payments from U.S. sources, such as Substack or its payment processors, and these platforms require a U.S. taxpayer identification number for reporting purposes, you will need an ITIN. Even as a non-U.S. resident, you must comply with U.S. tax reporting requirements.

How long does it typically take to renew an ITIN?

The processing time for ITIN renewal can vary. When applying through a Certified Acceptance Agent (CAA) like itin.net, the process typically takes 5–10 business days. If you mail your application directly to the IRS, it may take longer.

Can I renew my ITIN without filing a U.S. tax return?

No, you cannot renew your ITIN without submitting a valid U.S. federal tax return along with your Form W-7 application. The tax return serves as the primary reason for needing the ITIN.

What if my passport has expired? Can I still renew my ITIN?

If your passport has expired, you may still be able to renew your ITIN using other acceptable identification documents. However, a valid passport is the preferred and most straightforward document for proving identity and foreign status.

Will the U.S.-Denmark tax treaty affect my ITIN renewal?

The U.S.-Denmark tax treaty primarily affects how your income is taxed and potential withholding rates, not the process of renewing your ITIN itself. However, correctly applying treaty benefits on your U.S. tax return filed with your W-7 is crucial.

What is a Certified Acceptance Agent (CAA) and why use one for ITIN renewal?

A Certified Acceptance Agent (CAA) is an individual or entity authorized by the IRS to assist taxpayers in obtaining ITINs. Using a CAA like itin.net allows you to have your original identification documents verified on-site, eliminating the need to mail them to the IRS, and can expedite the overall process.

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