How far back the IRS can reach, and when the clock never starts

It is the period during which the IRS can assess additional tax for a year. Once that period expires, the year generally closes and the figures you filed stand for good.

A second, separate clock governs collecting tax the IRS has already assessed. The two run on different rules, so a closed assessment period does not stop collection of an existing debt.

A third clock governs refunds. That one limits how long you have to claim money back, rather than how long the IRS has to ask for more.

Three years, measured from the due date including extensions, or from the date the IRS received a late return, whichever is later. The IRS page on the time it can assess tax sets that out.

So a return filed on time in April generally closes three years afterwards. Filing late pushes the closing date out accordingly.

That period covers the ordinary case. The exceptions below are what matter for anyone with foreign income.

When a return leaves out a substantial share of income. The IRS extends the period to six years where a return omitted more than a quarter of the gross income that belonged on it.

Foreign income makes that threshold easier to cross than people expect. A correct salary sitting alongside an unreported rental profit can tip a whole year over the line.

So the six-year rule is not reserved for serious cases. It can catch an honest omission of a single significant item.

Then no clock ever starts for that year, which is the detail that catches people out. The IRS states that where you did not voluntarily file a required return, it can assess tax at any time.

This is the single most important point for anyone behind on American filings. A year from a decade ago is not safe simply because it is old.

Filing the return starts the statute of limitations running. So the way to close an old year is to file it, not to wait it out.

That is also why the formal routes cover a fixed number of years. They give a defined package rather than an open-ended history.

It can, and this catches people who did file their returns. Where a required international information return was never filed, the assessment period for that year can remain open until the form arrives.

The instructions for Form 8938 explain that the period may stay open for all or part of the return until three years after you file the missing form.

So a tidy-looking history of filed returns can still leave years open. Missing forms on foreign companies, trusts or funds have similar effects.

So check which forms each year actually required. The list is longer than most people realize once foreign accounts, funds or companies are involved.

There is no limit at all, and the rule says so in plain terms. A false or fraudulent return, filed with intent to avoid tax, stays open to assessment however long ago somebody filed it.

That rule stays narrow in practice, because the IRS must prove fraud rather than assume it. Honest mistakes, even large ones, sit under the ordinary rules.

It is worth naming precisely because people fear it wrongly. Not knowing about a filing duty is not fraud.

Generally ten years from the date of assessment, which runs quite separately from the assessment clock. The IRS page on the time it can collect tax explains that period and what changes it.

Several events pause the clock. Installment requests, offers, bankruptcy and certain appeals each suspend it during review.

One matters particularly to expatriates. Living outside the United States for six months or more suspends the collection period, and returning extends it further.

Three years from filing the return or two years from paying the tax, whichever falls later. So this statute of limitations runs against you rather than for you, and missing it costs real money.

The IRS page on claiming a credit or refund sets out that deadline. A refund left unclaimed past it is simply lost, even where the return was genuinely wrong.

It matters most for people who overpaid through withholding and never filed. The money is real, and the window is not indefinite.

No, because foreign account reports sit outside the tax code altogether. You file them with a different agency, and their penalty rules therefore run on a period of their own.

So treat them as a separate exercise from the outset. Our guide to Form 8938 and the FBAR explains how the two regimes differ.

In our practice we see people close their income tax years and forget the reports completely. The two clean-ups relate to each other without overlapping.

Yes, and the IRS sometimes asks you to. Where an examination is still running as a year approaches its closing date, it may request a written agreement extending the assessment period.

Agreeing is not automatic, and refusing has consequences of its own. The IRS can simply assess what it believes is due before the deadline, leaving you to dispute it afterwards.

So treat such a request as a decision rather than a formality. It is worth taking advice on before signing.

Any extension should be limited in scope and time. A narrow agreement is very different from an open one.

Britain works to fixed periods rather than an open-ended one. HMRC can generally assess four years back, six where tax was lost carelessly, and twenty where it was lost deliberately.

Certain offshore matters carry a twelve-year period. So a British year usually closes at some point, even where something went wrong.

That contrast surprises Americans in Britain. The British clock keeps running whatever happened, while the American one may never have started.

Both clocks can run at once for an American in Britain. Closing one country tells you nothing about the other.

It affects them, though not in one simple rule. Penalties tied to a tax assessment generally follow that assessment period, so a closed year usually closes the penalties attached to it.

Information return penalties behave differently, because the year can stay open until the missing form arrives. That keeps the related penalty exposure alive as well.

Our guide to delinquent FBAR procedures covers the narrower route for missing reports, which is often the cheapest way to close that exposure.

It means that waiting does not help you at all, which is the opposite of most people's instinct. Unfiled years stay open indefinitely, so the passing of time closes nothing whatsoever.

The formal catch-up routes exist for exactly this reason. Our guide to streamlined filing explains a package covering a defined number of years rather than everything you ever missed.

So filing is what creates finality. Silence simply preserves the exposure.

Yes, and starting that clock is precisely the point of filing one. The statute of limitations for a late return generally runs three years from the date the IRS receives it.

So a set of catch-up returns filed this year starts closing those years from now. Each one has an end date once it exists.

Missing information returns still need attaching. A return filed without them may leave part of the year open regardless.

This takes an hour with your filing history in front of you. It is worth doing before deciding anything else.

Write down the dates, because the answers depend on them rather than on impressions.

Take an illustrative example: an American in Cardiff filed nothing for six years, then filed the last two correctly when she learned about the obligation.

The two filed years each start their own three-year period from the date she filed. The four earlier years remain open, because nothing has ever started their clock.

She also held a foreign fund that required an annual form. Those years stay open until she files the missing forms, whatever else she does.

Filing those four years is what would finally start their clocks. Until then, they simply sit there indefinitely.

The first is believing old unfiled years expire. They do not, and the IRS says so plainly.

The second is assuming a filed return always closes after three years. A large omission or a missing foreign form can extend that considerably.

The third is confusing assessment with collection. A closed assessment period does not remove a debt that was already assessed.

The fourth is forgetting the refund clock. It runs while you decide, and an overpayment eventually stops being recoverable.

We map which years remain open and which have closed, through our US federal returns service, including the effect of missing forms. That map usually makes the decision obvious.

If you are unsure how far back your exposure runs, send us your filing history and we will set it out at a fixed fee agreed first. This article is general information, not personal tax advice; take advice on your own facts from a qualified adviser.