In answer to your question, there actually two
separate disclosure forms that can be required for those with "control" over a foreign bank account; each also has different
reporting rules.
One disclosure document is known as IRS Form 8938, and can be
attached to the relevant yearly personal Form 1040 tax return. The other is FinCen
Form 114, which can only be filed via the internet. The following
Internal Revenue Service webpage describes them in some detail, and provides
their reporting requirements:
https://www.irs.gov/businesses/comparison-of-form-8938-and-fbar-requirements
Please note that while Form 8938 is included
in TurboTax, FinCen Form 114 is not (as when it is required, it must be separately filed using a specific US Treasury Department webpage). Note that you can get to the right page by using a link embedded in the IRS comparison webpage (linked above).
Now then, in reference to your original question, we can look to the IRS summary section (on that comparison webpage) titled "When do you have an interest in an account or asset?" From there we see that for Form 8938 purposes, this particular disclosure form is not required purely because you may have signatory authority over a company's foreign back account . . . unless you would otherwise have to report "any income, gains, losses, deductions, credits, gross proceeds, or distributions from holding or disposing of the account" on you personal tax return. For most employees of mid-size to larger businesses, then, this would mean that no, you don't need to file Form 8938 just because you have signatory authority over one or more foreign accounts owned by your employer.
On the other hand, the rules for FinCen Form 114 are different. Even though there is currently a proposal under consideration to exempt certain financial professionals from the existing rules (which you can read about in detail on the FinCen Form 114 webpage), it is currently a requirement that anyone (whether they "own" the foreign account outright or not) should file FinCen Form 114, as long as they have signature authority over the account, or have the power to "control the disposition of assets" from within the foreign account.
In conclusion, then, if you have the power to sign payments, or to move money, within a foreign company-owned bank account, then you don't need to file Form 8938 with your personal income tax return; but you should file FinCen Form 114 (at the Treasury Department website) just to protect yourself in the current tax year (even if the rules are changed in the reasonably near future).
One last point here is worth mentioning: although there may be a requirement to disclose, there is never any actual tax due with filing Form 8938 or FinCen Form 114.
Thank you for asking this important question.
