The six digits posted every January to a house you sold in 2014

Figures relate to tax year 2025-26 (UK) · 2025 (US)

Your return gets rejected in April and nobody can tell you why. The error code refers to a number you have never seen.

Somewhere in America a letter went out in early January carrying six digits. It reached an address you left a decade ago.

The identity protection PIN is a sound defence against refund fraud and an awkward obligation once you hold one. For somebody in Britain the retrieval problem is the whole story.

Key takeaways

• An identity protection PIN is six digits and changes every year.
• Without it an electronic return is rejected outright.
• The annual notice goes to the address the IRS holds.
• Retrieving it online needs identity checks that fail abroad.
• Opting in is voluntary for most people, and reversible.
• Identity theft victims are enrolled and cannot opt out.
• Updating your address matters more than anything else.

What is an identity protection PIN?

A six digit number the IRS issues to a taxpayer, which must appear on any return filed under their details. It stops somebody else filing a fraudulent return in your name to claim a refund. According to IRS guidance on the programme, it changes each year.

Anybody with a valid taxpayer number can request one voluntarily.

Victims of identity theft receive one automatically instead.

Why does it matter so much abroad?

Because every route for retrieving it assumes an American address or an American identity footprint. The replacement notice posts to the address of record, and the online retrieval runs through verification that regularly fails overseas. Neither assumption fits somebody in Britain.

So the protection works perfectly while the number reaches you.

Everything goes wrong the year it does not.

A worked example

Take an illustrative example. An American in Edinburgh opts in during 2024 after reading about refund fraud.

The first year works fine, because she obtains the number online at the time. In January 2025 a fresh notice goes to her old address in Oregon.

Her April filing is rejected. She cannot retrieve the new number because her verification lapsed with a changed phone.

She files on paper instead, and the return takes seven months to process. The protection cost her more than it saved.

Protection against inconvenience

How do you get one?

Through your online account, which issues the number immediately once identity verification succeeds. That same verification is the obstacle for most expatriates. Where it works, the number appears on screen and you print it straight away.

Our guide to IRS online access from Britain covers the verification routes.

Alternative application routes exist but run on much longer timescales.

What happens if you lose it?

Your electronic return gets rejected and you have two options. Retrieve the number through your online account, or file on paper and accept a long delay. Nobody at the IRS will read the number out over the telephone.

A replacement notice posts to the address of record rather than to you.

That is why the address matters more than any other detail here.

Can you update the address properly?

Yes, through a short change of address form that takes several weeks to process. Doing it long before January is the difference between receiving the notice and chasing it. A forwarding arrangement with a relative is not a substitute.

Our guide to requesting transcripts from abroad covers the same address rule.

Most of the trouble we see traces back to a stale address.

Should an expat opt in at all?

It depends on how reliably you can retrieve the number each year. Somebody with working online access and a current address gains real protection at low cost. Somebody who fails verification is taking on an annual risk of rejection.

In our practice we suggest opting in only once online access works.

Order of operations matters more than the decision itself.

Can you opt out again?

Most voluntary participants can, through the same online account that issued the number. Victims of confirmed identity theft cannot, because the enrolment is protective rather than optional for them. The distinction follows how you entered the programme.

Opting out takes effect for the following filing season.

It does not undo a rejection that has already happened.

What is the fraud it actually prevents?

Somebody filing a return in your name early in the season and claiming a refund before you file. The refundable credits are the target. For 2025 the refundable child credit alone reaches $1,700 per qualifying child.

Expatriate taxpayer numbers are attractive precisely because the real owner files late.

Filing early is itself a partial defence.

Does your preparer need the number?

Always, because the return cannot be transmitted without it. Send it securely rather than by ordinary email, and send it each year rather than assuming last year's still works. Preparers cannot retrieve it on your behalf.

Diarise it for early January alongside the notice.

A missing number in April is the commonest cause of a late filing.

Do dependants need one too?

They can have one, and in some cases it matters more than yours. A child's number is a frequent target for fraudulent dependency claims. Where a child already has an identity protection PIN, the return needs that one as well.

Keep the family numbers together in one secure place.

Losing a child's number blocks the return just as effectively.

What about an ITIN holder?

The programme extends to individual taxpayer identification numbers, though the verification route differs. An expired number causes a separate rejection that looks similar but has a different cause. Check the status before blaming the PIN.

Our guide to applying for an ITIN from Britain covers renewal.

Two separate problems can easily produce the same error message.

Does it affect paper filing?

A paper return without the number is accepted but held for additional checks, which adds months. Processing from abroad is slow enough already. The delay matters most where a refund is due.

Include it on the paper form if you have it.

Leaving it blank is better than guessing a wrong number.

What if somebody already filed in your name?

Then you report the theft and file on paper with the supporting form attached. The IRS investigates and the process routinely takes a year or more. A PIN issues automatically once the case is confirmed.

Living abroad slows every stage of that process.

Keep copies of everything you send, because correspondence goes missing.

Does it protect your state filing?

Not directly, since states run their own systems and some issue their own numbers. A federal PIN does nothing for a state return. Anybody still tied to a state should check that state's own position separately.

Our guide to state tax for expats covers breaking residence.

Most expatriates have no state filing at all, which removes the question.

Does it change how early you should file?

It removes most of the pressure, because a fraudulent return cannot get through without the number. Without one, filing early is your main defence, since the first return submitted under a taxpayer number usually wins the race.

Expatriates tend to file late, often on the June or October deadlines.

That long gap is exactly what makes an overseas number attractive to a fraudster.

What if you move house in Britain?

Tell the IRS, because the address of record governs where the January notice goes. A British address works perfectly well on the form, and many expatriates never realise they can use one. Keeping a relative's American address instead is what causes the misses.

Update it in the autumn rather than the spring.

Processing takes several weeks, and January comes round quickly.

Does a joint return need two numbers?

If both spouses hold one, then yes, both appear on the return. Where only one spouse is enrolled, only that number is needed. A non-American spouse with no taxpayer number is outside the programme entirely.

Check each person separately before filing season.

One missing number rejects the whole return, not just that person's part.

Is there any cost?

None at all, which is worth saying since scam sites charge for it. The IRS issues the number free through its own service and never asks for payment. Anybody requesting a fee for one is not the IRS.

The same applies to anybody telephoning to ask for your number.

The IRS does not ring taxpayers to collect it.

Does a preparer hold one for their own filings?

Preparers have a separate identifier for signing returns, which is not the same thing at all. Yours protects your taxpayer number while theirs identifies them as the person who prepared the return. Confusing the two is common and leads to rejected filings.

Only your own number goes in the taxpayer box.

A preparer cannot substitute theirs, however convenient that would be.

What if you stop filing altogether?

The number keeps issuing each January until you opt out, because enrolment is not linked to whether you file. Somebody who renounces citizenship and stops filing should opt out rather than ignore the notices.

Otherwise the letters keep arriving at whatever address is on file.

That is a small privacy problem as much as a tax one.

What records should you keep?

Keep each year's notice or screenshot, the date you obtained the number, and a note of the address the IRS currently holds for you. Those three items prevent almost every problem described above.

Store them where you store passwords rather than in email.

Delete last year's number once the new one arrives.

How to manage an identity protection PIN

1. Confirm your online access works before opting in.
2. Update the address the IRS holds for you first.
3. Obtain the identity protection PIN and record it securely.
4. Diarise early January to collect the new one.
5. Send it to your preparer through a secure channel.
6. Check whether any dependant also holds one.
7. File early, since that itself deters fraud.
8. Opt out if retrieval proves unreliable year to year.

Mistakes and penalties we see with an identity protection PIN

The first is opting in before online access works. The protection then becomes an annual obstacle.

The second is leaving a stale American address on file, which sends the notice somewhere useless.

The third is reusing last year's number, which rejects the return just as a missing one does.

The fourth is forgetting a dependant's number, which blocks the whole filing.

How US UK Tax Accountants helps

We check the address of record before filing season rather than during it, because that single step prevents most of these problems. Then we collect the numbers for the whole family in one go.

Where a return has already been rejected, we work out whether the cause is the PIN or something else. Our US federal returns service covers the filing itself.

If your return bounced and nobody can explain the code, get in touch and we will diagnose it.

Last reviewed 17 October 2026. This article is general information and not personal tax advice. Procedures change, so confirm the current position before relying on it.