If your note is already on "non-accrual" with Fiserv and you are now charging off the remaining Principal Balance - You are charging off the remaining Principal Balance. For example you had a principal balance of 10,000 when placing note into non-accrual status. You collected 5 payments @ 200 each for a total of 1,000 which reduce the principal balance to 9,000. You are charging off the remaining 9,000. You do not "recognize" the interest portion of the payments received and the impact to your ALLL is just the 9,000 charge off. Of course if at some point you recover additional monies those would be recognized as recovery to your ALLL balance until the 9,000 is recovered and then you may recognize the interest (if you are lucky enough to recover it).
Right, if I remember correctly, what FiServ has said is that you can either apply the recovery payment directly to Recoveries GL, or you can apply it to the loan and (if set up right) that payment will flow through to recoveries.