The BT Quantum phone system is no longer supported by BT Business. Support ended on 30 September 2025, and we won't update this page if anything changes with the product.
If you're looking for a replacement system, check out all our cloud-based phone systems.
The conference facility on your BT Quantum lets you hold a three-way conversation between:
If you're on an internal or external call and want to add an external number:
If you're on an external call and want to add an internal number:
From a standard telephone:
You can find full details in the BT Quantum User Guide.