There are several apps available in the Shopify App Store that allow you to customize your order numbers. The most popular one is:
Cleverific Order Editor: In this app, there’s an edit option right beside your automatically generated order number. You can edit this number in any way, including adding letters, reducing or increasing the number of digits, or not using numbers at all. You can use this option to easily create unique markers for custom orders, wholesale orders, and more in the same Shopify store.
I hope this helps! Let me know if you have any other questions.
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