A return filed without a required Form 3520, 5471, 8621, 8858, 8865 or 8938 is incomplete and stays open to IRS assessment until the form is filed. Most carry penalties from $10,000 per form, per year. Missing FBARs, filed separately with FinCEN, carry their own penalties.

The fix: amended returns with the missing forms, plus six years of FBARs. Non-willful taxpayers abroad can usually file through the Streamlined Foreign Offshore Procedure, which waives the penalties. That door closes once the IRS contacts you.

The additional tax is often nil; the exposure is in the forms. We bring them current.