Deductions & credits

box 2 is supposed to be the balance at the beginning of 2021.

 from 1098 instructions: Box 2. Shows the outstanding principal on the mortgage as of January 1 of the
calendar year. If the mortgage originated in the calendar year, shows the
mortgage principal as of the date of origination. If the recipient/lender acquired
the loan in the calendar year, shows the mortgage principal as of the date of
acquisition.