Yes you can.
ServiceM8 can be setup to add a prefix, or suffix invoices with number or letters to suit your MYOB requirements. The only limitation is that MYOB can have a maximum invoice number length of 8 characters - so keep this in mind.
If you wish to continue raising non-servicem8 based invoices in MYOB, we recommend you have an invoice suffix of "SM" - as this will prevent MYOB from switching your next invoice # to the last ServiceM8 raised invoice # when you manually raise invoices (saving frustration).
You can now adjust your job number through your account.
To do this: