The order IDs on your account will automatically start at ‘1’. The ID numbers for new orders will then increase in consecutive order (meaning the next ID would be ‘2’ then ‘3’ and so on).
However, it is possible for you to change the number that your order IDs begin at.
To do this first select Orders > View Orders from the menu.
On the top right of your screen you will then see a Settings button:
Selecting this will bring up a new screen which will look like this:
Enter the number you would like your next order ID to be and click Save Changes. Your order ID numbers will then carry on consecutively from the number you chose. You can change this number at any time.