The IRS has revised and updated the Frequently Asked Questions (FAQs) posted on the IRS website for payers who need to know about Form 1099-K reporting. The updated FAQs are at
http://www.irs.gov/newsroom/article/0,,id=249029,00.html. They cover developments as recent as the postponement of the start of backup withholding on Form 1099-K payables (to the beginning of 2013 instead of 2012), and the offer of tax penalty relief for payers who have errors in their Form 1099-K filings for 2011 (if the payer shows that a good-faith attempt to file accurately was made).
The FAQs also cover the new IRS decision that third-party payment settlement organizations do not report Merchant Category Code (MCC) numbers on the 1099-Ks they file. Third-party settlement organizations are to leave box 2 (the MCC box) on the 1099-K blank. The other type of 1099-K filer, the merchant acquiring entity, is expected to enter a MCC in box 2. If the filer has more than one MCC for a payee, the filer has the option of either using the MCC number that applied to the largest portion of the total gross proceeds for the payee or filing multiple 1099-Ks for that payee (one 1099-K for each MCC).
The final version of Form 1099-K has still not been published by the IRS. A 1099-K and Instructions were released by the IRS but were then withdrawn in September and October as the IRS was still hammering out the details.