that is made to collect an expense
that is incurred
in a previous billing period
. This may be an adjustment
that is due to an error
, or it could be for the purpose of collecting an expense that was not billable until a later period due to issues of timing. When possible, it is best to avoid having to back charge for products or services
. Because customers do not expect back charges, they can be confused with billing errors and they often take longer to collect.