Solo 401K? Reminder: Form 5500-EZ due 31 Jul
This only affects a minority of folks here, but if you have a solo 401K with a balance that exceeded $250K on 31 Dec 2017, you likely need to file a Form 5500-EZ (or similar form) by 31 July. It is easy to forget, for many, since the filing deadline is different from the standard 1040 forms.
The penalty for failure to file on time is considerable. The IRS will accept some excuses (ask me how I know), but it is a PITA to go that route and filling out the 5500-EZ is very, very simple.
End of public service announcement.