The House BL (HBL) is issued by the NVOCC (Non vessel operating common carrier).
This BL will often be released in conjunction with the Master BL (MBL) because it can serve different purposes. In addition to representing the contract between you and the NVOCC, it can also cover an extended routing that the MBL doesn’t. For example, the MBL might only take your cargo up to the port of Mombasa –because that’s where the ocean portion ends. But if you’ve contracted your forwarder to take this inland to Kampala, Uganda, then the NVOCC will issue a House BL as an umbrella covering the additional move. Depending on the specifics of the destination country, the House BL can be used to clear Customs.