A post office box that a company sets up as part of a service offered by its bank to process and deposit checks that the company receives from its customers. The company notifies its customers that they must mail their payments directly to the post office box. The bank collects the checks from the post office box and deposits them into the company's bank account. Companies use lockboxes to speed up the collection and deposit of check payments that they receive through the mail from their customers, which gives them quicker access to the cash proceeds of their receivables.

Most banks that provide lockbox services offer wholesale and retail lockboxes as separate services. Each of these has different attributes and is suitable for different types of businesses.

For more information on lockboxes, see Practice Note, Cash Management: Lockbox Services.