This data comes from the TAX file. This file is created automatically at year-end and populated with things like dividends, interest paid, and other details to be reported to the IRS and printed on tax forms.
When it comes to Property Tax and PMI, things get a little complicated. Over the years the IRS has shifted back and forth as to (a) whether we are obligated to report this data to the IRS or (b) whether it can simply be reported to members via the 1098 form, regardless of whether the IRS wants it. Because this seems to change frequently, for the latest interpretation and technique we are using, always refer to your most current Year-End Processing Guide, available on the Reference Materials page of our website.
The TAX file can be adjusted manually at any time using Tool #899 Update IRS Tax Information.
Remember that you can update information for the current tax year even before December 31. During year-end processing the system will simply add any additional amounts to whatever you have entered manually. You can also adjust the tax file after January 1. Just be sure to enter the correct tax year on the initial screen so that the data is recorded for the proper tax period.