Banks that have foreclosed on units become responsible for paying assessments to the association on the first of the month following the judicial sale. (You can look up a judicial sale date by the property's PIN here.)
In order for the bank to begin paying assessments, they will require the association to submit a current account statement and a W-9 showing the association's Federal Employer Identification Number (FEIN) as assigned by the IRS. If you have units currently going through a foreclosure, make sure you have these items in order so that you can begin collecting assessments from the foreclosing bank as quickly as possible.