Definition
Auto Number is a custom field type in Salesforce that automatically generates a unique, sequential number for each new record created on an object. Administrators define the display format (such as a prefix and number of digits, like 'CASE-{0000}'), and Salesforce increments the number automatically. Auto Number fields are commonly used for Case numbers, Invoice numbers, and other identifiers that require unique sequential values.
Real-World Example
At their company, an admin at Redwood Financial leverages Auto Number to ensure the Salesforce org runs smoothly and securely. They configure Auto Number during a scheduled maintenance window, test it in a sandbox first, and then deploy to production. The result is tighter security and a more streamlined experience for all 200 users in the org.
Why Auto Number Matters
Auto Number is a custom field type on Salesforce objects that generates a unique, sequential value for each new record. When configuring an Auto Number field, administrators specify a display format (like CASE-{00000} which produces CASE-00001, CASE-00002, and so on) and a starting value. Salesforce then increments the number automatically whenever a new record is created, and the value is set once and cannot be changed afterward.
Auto Number fields are commonly used for human-readable identifiers like Case Numbers, Invoice Numbers, Project Codes, and Ticket IDs where users need a unique reference that's shorter and more memorable than a Salesforce record ID. One important thing to know: Auto Number sequences can have gaps when record creation fails mid-transaction or when records are deleted, so they should not be used as audit trails that require no gaps. For that, you need different patterns.
How Organizations Use Auto Number
- •Redwood Financial — Uses Auto Number fields on a custom Invoice__c object with the format INV-{YYYY}-{0000}. Each invoice gets a year-prefixed sequential number that's easy for customers and AP staff to reference verbally.
- •NovaScale — Configured an Auto Number field as the primary display name for their Work Order custom object. Field technicians reference work orders by number in radio calls and paperwork, so a clean, unique identifier matters.
- •Cyberdyne Co — Learned the hard way that Auto Number gaps are expected. Their finance team raised an alarm when invoice numbers skipped from 1044 to 1046, but the missing number was just a cancelled save, not lost data.