Quarterly Estimated Tax Payments?
 

curious as to how many file these solely related to officiating income?

Never have. And never will. I do not know of any sports officials that file them.

MTD, Sr.

If you are an "amatuer" ump, doubtful you would need to. Probably don't make enough in a quarter if you track expenses as well. If you're pro, probably don't need to as withholding is probably done. So very unlikely anyone is doing so.

Schedule C on the annual 1040.

General Rule

You Must Pay estimated tax for 2007 if both of the following apply.

1. You expect to owe at least $1,000 in tax for 2007, after subtracting your withholding and credits.
2. You expect your withholding and credits to be less than the smaller of:

-------a. 90% of the tax to be shown on your 2007 tax return, or
-------b. 100% of the tax shown on your 2006 tax return. *Your 2006 tax return must cover all 12 months.
--------* Certain taxpayers with higher adjusted gross income must substitute 110% for 100%. Refer to Chapter 2 of Publication 505, Tax Withholding and Estimated Tax, for the income amounts that the higher percentage applies to.


If you have other sources of income and have withholding, it's unlikely you'll need to pay quarterly estimated taxes. i don't know anyone who does. Pay it at the end of the year, if you owe anything at all.