For Cap 1 I used:
PO Box 30281
Salt Lake City, UT 84130
That was back in 2007 after a 2004 BK. They deleted the lates (4 total), and updated the account to paid, closed/never late following a GW letter.
For Care Credit I used:
P.O. Box 981439
El Paso, TX 79998
Also in 2007 after 2004 BK. Account was in good standing prior to BK. No balance. Just an open acct. Filed the BK, did not include this acct in the BK. However, Care Credit included itself and reported as closed by credit grantor and included in bk. Which, I learned they are allowed to do, even if we did not include the acct ourselves. Sent a GW letter saying acct had been in good standing prior to bk. No balance at the time of filing, or the year priot to filing. Asked them to not report as included in bk and consider re-opening acct. Did not re-open acct. but did report the acct as a positive, paid/never late acct. Still closed by credit grantor, but that doesn't relfect negatively.
Good luck!
