Does everyone perform a full administration for their Solo K clients?

We treat these plans like any other - use our document, collect data, prepare a val, with or without tax return as needed. Yes there are some shortcuts - maybe a simple phone call to collect data, confirming no employees and income. We charge less than for a "regular" plan. But sometimes they are a timesuck because these are often people who think you can read their mind and can't be bothered to answer your data collection request.

In theory, no "admin" is needed - just a simple doc and have the accountant calc the contribution and put it in, right? But we've seen accountants who think you can pay a salary of $100K to an S corp owner and max out (dollarwise) on contributions. And accountants who use their own software and don't know how 401(k) contributions work vs. profit sharing. Or we see here on the board where someone has been making Roth contributions and now wants to take a distribution but the money is all commingled and no one has been tracking it separately.