# Reference Numbers PAI assigns two reference numbers to every project, at two different points in the lifecycle. They're not duplicates — they serve different purposes, appear on different documents, and signal different stages of the work. --- ## Estimate Number When you create a project, PAI immediately assigns an estimate reference number starting at 100 and incrementing automatically. By default this uses the prefix **E** (E100, E101, E102, etc.), but the prefix is configurable in Organization Settings — change it to any letter or string and PAI restarts the count from 100 with the new prefix. PAI enforces uniqueness across all reference numbers and will never assign a duplicate. The estimate number is the project's identity during the bidding phase. It appears on estimate documents shared with clients and can be used to search and navigate to the project from anywhere in the app. --- ## Project Number When an estimate version is approved, PAI assigns a project reference number, also starting at 100 and incrementing automatically. By default this uses the prefix **P** (P100, P101, etc.), and like the estimate prefix it can be changed in Organization Settings. The project number signals that a bid has become a confirmed job. It replaces the estimate number as the primary identifier on all production documents — call sheets, budget reports, vendor invoices. The original estimate number remains associated with the project for historical reference, but the project number is what you and your vendors cite going forward. --- ## Job Codes If your organization uses a custom numbering system — for tracking jobs against an external accounting system, a client numbering convention, or any other reason — you can enable **Job Codes** in Organization Settings. Job Codes are fully customizable alphanumeric identifiers (e.g., `JOB-2026-0421`). They cannot contain spaces and must be unique across the workspace. When Job Codes are enabled, you can assign one during project creation. Once assigned: - The Job Code becomes the **primary identifier** on all external documents — it replaces both E### and P### in client-facing materials - The system-generated E### and P### numbers remain active internally and in search, but take a secondary role - Job Codes can be searched and used for navigation just like E/P numbers > [!note] > Job Codes are optional per project even when the feature is enabled. Projects without a Job Code continue using E### and P### normally. --- ## Using Reference Numbers All reference numbers — E###, P###, and Job Codes — are searchable via the global search (Cmd+K / Ctrl+K) and any project list filter. In organizations with large project volumes, searching by reference number is usually the fastest way to navigate to a specific project.