# BT-11 — Project reference

> https://billhorse.com/en/terms/bt-11/

Identifier of the project the invoice relates to. Helps the buyer allocate costs.

## Where does it live in the XML?

- UBL: `cac:ProjectReference/cbc:ID`
- CII: `rsm:SupplyChainTradeTransaction/ram:ApplicableHeaderTradeAgreement/ram:SpecifiedProcuringProject/ram:ID`