To easily identify invoices and credit memos we used to create the prefix CR- for credits and QB would remember and sequentially create new Credit Memos with the prefix (e.g. CR-100, CR-101, CR-102) and leave the invoices alone.  The credit memos would continue with the CR prefix and the invoices without a prefix.  At some point this stopped working and now wants to put the CR in front of invoices. Is there any way to get the numbering to be different and accept the letter prefix for just the credit memos?