If your business requires the need for a proposal number or “Control Number”, you can enable this in your Settings. Only Owners of the account can enable this feature. You can do this under your Settings > Deliveries:
You can set the start number to whichever number you’d like. Keep in mind this will only accept numeric characters. To use this functionality, you must use a Merge Tag in order to make the Proposal Number display on the proposal. You can locate this Merge Tag while editing the proposal and clicking the Merge Tag icon
and clicking on the {{proposal_control_number}} option.