WooThemes - WooCommerce Sequential Order Numbers Pro v1.6.5
Tame your WooCommerce Order Numbers
The WooCommerce Sequential Order Numbers Pro plugin allows your store to have sequential, rather than random, order numbers. Additionally you can customize your order numbers by setting a starting number, whether to append a "hash" (#) symbol to the beginning of your numbers, order number length, and custom prefixes and suffixes. Instead of your order numbers looking like 15, 16, 37, and so on, they could now be WT-01000-UK, WT-01001-UK, or whatever format you prefer!