I use the expression “garbage in, garbage out” if an end of year census report is done incorrectly and the third party administrator (TPA) doesn’t pick up the error.
When given that census request at the beginning of the new year, you need to make sure that the information you provide is correct. When it comes to identifying employees as highly compensated and/or key employees, errors will come back to haunt you in terms of incorrect compliance testing and possibly failed required minimum distributions.
TPAs aren’t baby sitters and most will assume that then information you provide is correct, so it’s on you to be right.