Already doing the workaround... but Service M8, Woocommerce update the system 5-6 times a day and Splynx does an update every morning... all have different numbering schemes.

I am sending out recurring customers now with Service M8 reference numbers as these generate throughout the month and send before I get the chance to change the numbers! Causing duplication and confused customers as there last invoice was INV-003279 and its just jumped to SMI-22 (Service M8 designation!) and now Service M8 has a duplicate record so stops syncing....!!!