​ ​ ​ ​ ​ ​The Order Number: 

Odoo 18: Indicates the number of consecutive sales done without closing the register. If multiple sales are processed in a single day in an unique PoS if session is closed or as well without closing the register, the order numbers will range from 001 to 999, restarting at 001 after reaching 999.

Odoo 17: This logic for order numbers in Odoo is based on identifying distinct sessions and grouping sales within those sessions. Here's a breakdown:

Session-Based Order Numbers:

1. • The first digit(s) (1XX, 2XX, 3XX, etc.) is based on the last number of the session you are currently working at. For example:
   • • If you are working on session 4; the order number starts with 4XX
     • If you are working on session 137; the order number starts with 7XX

Repeat of Third Position:

1. • If the third digit repeats (for example, 103 appearing twice), it indicates that the user did not log out after a sale, but instead accessed the backend and then returned to continue the sale. The order number 103 appears again, but both receipts are still separate, each with its own journal entries.

Sequential Sales Without Logging Out:

1. • If multiple sales are made in one session without logging out, the order number increments sequentially; for example, if you are in session 1, it will go from 001 to 099. After reaching 099, the sequence resets to 001.

​ ​ ​ ​ ​ ​The Receipt Number:

Odoo 18:

Format: YYLL-SSS-FOOOO            

* YY is the year            

* LL is the login number (proxy to the device)            

* SSS is the session id            

* F is 1 or 0 (1 if sequence number is generated from client)            

* OOOO is the sequence number.    

Odoo 17: Let's follow this example: 00002-002-0001. The first numbers before the hyphen (00002) indicate the session count in the history since you started using the Odoo point of sale, meaning you have only opened 2 sessions in that POS. The three numbers within the two hyphens (002) indicate how many times you have exited to the backend (the general Odoo menu) without closing the session at the POS. The last numbers after the hyphen (0001) indicate the consecutive sales made