Tech Squares currently has 3 different ways in which callers get paid:
1. People the club pays directly who teach things are required to be MIT employees, and are paid through MIT payroll. This includes our regular Tuesday callers and cuers, and the Monday rounds class. This process involves a bunch of one-time new employee logistics. Once set up for the first time, this approach does not involve any ongoing paperwork on the caller's end (as long as they call every now and then, and don't go for several years or so without calling (there are some details I'm omitting here)). This approach involves significant per-employee overhead, so is probably best limited to those teaching or who are being paid frequently. This approach allows a required admission price to be clearly specified.
2. Other people the club pays (such as irregular Tuesday cuers) are paid as contractors, and paid by a check from MIT. This involves signing an MIT contract and completing a W-9 form. As long as Tech Squares gets the paperwork 3 weeks ahead of time, there is no problem getting the check to the caller on time. We've had problems in the past where callers did not get the paperwork back early enough (in some cases, because they did not receive the paperwork early enough), and we can do exception processing to get checks as soon as next-day (or even possibly same-day), but the exception processing should not be the standard mechanism. This does require somebody to keep following up to ensure the contracts are in, and requires more per-event overhead (though less per-payee overhead) than making somebody an employee does.
3. Other events like CCS and higher-level squares classes have chosen to use the voluntary-contribution-based model, but the other options above are also available if the event organizers choose to do so. This process does not involve any paperwork, but restricts what Tech Squares/the dance organizers can say about pricing, but does not restrict what the caller can say. (As a side note, the term "donation" is not allowed.)
There's also an email (and GDrive document) "Changes in Money Collection at CCS-like events" that Veronica sent to the officers' list in June 2016 that talks more about some of the options.