When it becomes clear that a customer doesn’t intend to pay you of their own free will, turning things over to another party probably isn’t a bad idea. For example, customers that flatly deny owing you money, despite your records, are very difficult to deal with without help.
A customer making repeated, groundless claims and complaints for the sole reason of getting out of a payment, is another tell-tale sign that your business may have a problem on its hands. In cases like this, it is a good idea to send a final warning notice, attempting to create a fair repayment plan. If no action is taken by the other party, it is then time to seek help from professional debt collectors.
Another obvious sign of trouble is when a delinquent debtor changes their address or telephone number without notifying you or providing forwarding information. In cases like this, you should immediately get assistance from an agency that is willing to track down the customer and act upon the debt.