What percentage of US Citizens abroad actually file US taxes?

I've lived outside the US since 2009, in both the UK (twice) and Norway. In both places I've met scores of US citizens living abroad and/or dual US citizens (adults who have a US citizen parent but never lived in the US). In NONE of these cases (yes zero!) did I ever meet anyone who filed their US taxes or even knew about their requirement to do so.

Usually, they seem to not believe that there was any requirement for them to do so, and especially amongst the dual citizens who had grown up abroad, they would say things like "I am a Norwegian citizen as well, who has grown up in Norway, why should it be any business of the US government as to what I make in Norway?"

I consistently file my taxes each year, but does anyone know the actual percentage of US citizens abroad who actually do it? My anecdotal experience tells me the number is probably very small.

Does the IRS even have the manpower to come after all these people who don't file? Do they even have numbers telling them the number of US citizens (and dual US citizens) who are completely ignorant of US law?

The IRS publishes the number of returns claiming the FEIE and foreign tax credits but it is not possible to completely determine from this how many US persons, not US resident, are filing returns. But you can estimate it. Similarly the number of FBAR returns (now Financial Crimes form 114) is reported but this mixes in US resident returns. Again estimates can be made. From this one can tell that at a large proportion of US persons abroad do not file.

Good question.

Unless you have a US passport I can fully understand that US folks don't know that they should be filing taxes no matter where they are living.  (The requirement to file taxes is printed in the passport for those that care to read it).

Those without a passport are expected to self report that they are a USC to their banks when asked as part of FATCA.  I don't know how the IRS can realistically pursue USC's who have never had a US passport and I doubt very much it would be worth their while.  Every year over the past 5 years Congress has cut the budget of the IRS so they are shorter of manpower than ever which is why they have been shutting down IRS overseas offices.

Good question.

Unless you have a US passport I can fully understand that US folks don't know that they should be filing taxes no matter where they are living.  (The requirement to file taxes is printed in the passport for those that care to read it).

Those without a passport are expected to self report that they are a USC to their banks when asked as part of FATCA.  I don't know how the IRS can realistically pursue USC's who have never had a US passport and I doubt very much it would be worth their while.  Every year over the past 5 years Congress has cut the budget of the IRS so they are shorter of manpower than ever which is why they have been shutting down IRS overseas offices.

Actually, almost all of the dual citizens I spoke to who had grown up abroad, did, or at least at one time, had a US passport.

Does this mean that there are no hard numbers anywhere that shows what percentage of US citizens abroad actually file? I feel like I'm in a tiny minority actually doing it year after year.

I hope this horrible requirement is ended one day. This is the main reason the wife and I have separate accounts. Why should the US government know anything about wife's finances?

https://www.irs.gov/uac/soi-tax-stats-individual-foreign-earned-income-foreign-tax-credit

All you need to know now is:
How many US expats abroad are there? (Officially, no one knows.)
How many of those are above the filing thresholds and should be filing?
How many are below the filing threshold or how many have no income (children)?
How many form 1116 are filed from abroad (and not from US truly resident taxpayers)?

Two years ago I received a call from the IRS - at first I thought it was a hoax but it really was the IRS. Following the call we received an official letter stating that we needed to back file tax returns. We are both UK/US citizens.
Moved back to the UK in 2009 and hadn't filed taxes until receiving the call/letter in 2013.
Turned out we owed a small amount but the fines and interest had accumulated. We were let off the fines after writing a number of letters.
I would never have thought that we would be tracked down - but we were!

I would never have thought that we would be tracked down - but we were!

The long arm of the law can indeed be very long.

A couple of years ago we visited https://cascadebreweryco.com.au/Cascade Brewery in Tasmania (Cascade is the oldest operating brewery in Australia).  It was initially the site of a saw mill built in 1825 by 2 guys who had sailed from Britain.  However, one of them was a bankrupt and had left a load of debt back in Britain.  The authorities caught up with him and he was put in debtors' prison for 5 years until the debts were paid off.  When he got out he convinced his partner that they would make more money if they changed the operation from a saw mill to a brewery.