If you would like your invoice numbers to start from a particular number you are able to do this by updating the last invoice number generated in the account so that the next invoice number generated is that number +1
To do this:
1. Go to Setup> General
2. Under 'Invoice & Statement Layout' use the 'Last Invoice Number' field to enter your last invoice number
3. Click 'Save'
The system will then update the last invoice generated with that new invoice number. The next invoice generated in the system will be that number +1. All invoice numbers will be numbered sequentially thereafter.