Hi PSDA,
That sounds like one of those extra-fiddly STP migration situations. A good thing to check is the Xero STP setup, specifically whether the previous BMS ID from MYOB has been reported there. That’s what helps signal to the ATO that the Xero reporting is a continuation of the same payroll history, rather than a completely separate set of figures. If that piece hasn’t been carried through correctly, it can lead to the kind of duplicate income statement issue you’re seeing. If you’ve already checked that on the Xero side and it still hasn’t resolved the duplication, the next best step would be to contact the ATO directly so they can confirm how those historical lodgements should be handled from their end.
Cheers,
Doreen