A lockbox is a secure service provided by banks to process payments received by a company. It is primarily used to streamline the collection and processing of accounts receivable. Companies direct their customers to send payments to a designated P.O. Box, which is managed by the bank. 
Here's how it works:
1. **Mail Collection**: Customers send their payments, usually checks, to the lockbox address. This address is a P.O. Box controlled by the bank, not the company.
2. **Payment Processing**: The bank collects the mail several times a day. They open the envelopes, extract the checks, and any accompanying documents, such as remittance advice.
3. **Deposit and Recording**: The bank deposits the checks into the company's account. They also record the transaction details, which can include the payer's information, the amount, and any invoice numbers.
4. **Data Transmission**: The bank provides the company with detailed reports of the transactions. This can be done through electronic data interchange (EDI), secure online portals, or physical reports, depending on the company's preference.
5. **Reconciliation**: The company uses the data provided by the bank to update their accounts receivable records, ensuring that all payments are accurately recorded and reconciled.
Lockboxes are beneficial for companies with high volumes of payments, as they speed up the cash flow process, reduce the risk of fraud, and minimize the administrative burden of handling payments internally. They also provide a secure and efficient way to manage incoming funds, allowing companies to focus on their core business activities.