Migration

Fresh Start vs BMS ID Carryover When Changing Payroll Systems

There are two ways to handle year-to-date reporting when you change payroll systems: carry the old BMS ID and the year-to-date figures across, or make a fresh start where only leave balances move and the outgoing system finalises the year. For construction crews, a fresh start is almost always the cleaner option.

The two options

Carry the year across, or close it off?

Carryover keeps one continuous reporting stream by reusing the old Business Management Software ID and loading year-to-date figures into the new system. Fresh start closes the year in the old system, finalises it, and opens the new system with leave balances only.

  • BMS ID carryover

    What moves
    Year-to-date gross, tax and super, plus leave balances
    Risk
    Duplicated income statements and pay category mismatch on super application
    What the employee sees
    One income statement, if nothing goes wrong
  • Fresh start

    What moves
    Leave balances and history only, year-to-date closed in the old system
    Risk
    Low. Nothing is reported twice because nothing is reported twice
    What the employee sees
    Two lines for the year, same as changing jobs mid-year

The failure

How duplicated income statements happen

The old system has already reported gross, tax and super for the year under its own identifier. Load the same figures into the new system and the ATO holds both. The employee logs into myGov, sees roughly double their income, and the office spends a week explaining it and then unwinding it.

The reporting problem is not hard to fix. It is hard to notice, because it surfaces in myGov, not in your pay run.

  • Two systems, one financial year

    Both report against the same employee and period, and neither knows about the other.
  • The identifier is the switch

    The BMS ID is what tells the ATO whether this is a continuation or a new stream.

Super and categories

Pay category mismatch on carryover

Construction pay categories are not generic. Site allowances, all-purpose allowances, overtime, RDO buyback and travel each apply super differently. When year-to-date figures are loaded against a new category that applies super differently to the old one, the year's super base stops agreeing with the super actually paid, and the mismatch is only visible once the year is reconciled.

  • Super application is the trap

    An allowance that was super-bearing in one system and not in the other quietly changes the year's numbers.
  • Prior totals in payslip notes

    With a fresh start we put the closing year-to-date figures in a payslip notes section on the first run, so the crew can see the whole year without two logins.

Related: reconciling leave balances in dollars and the STP update event on go-live .

Employee comms

What to tell the crew

One short message, before the first pay run: you will see two income statements for this financial year, both are correct, both will be finalised, and your tax return adds them together. Nothing is missing and nothing is taxed twice.

Fresh start questions

What is a BMS ID?

The Business Management Software ID is the identifier the ATO uses to tie Single Touch Payroll reporting to a particular payroll system. Carrying the old ID into the new system tells the ATO to treat the reporting as one continuous stream instead of two.

Why do duplicate income statements happen?

They happen when year-to-date figures are loaded into the new system while the old system has already reported the same amounts under its own identifier. The ATO then holds two sets of the same income for the same period, and the employee's myGov shows inflated totals until it is corrected.

What does a fresh start actually move across?

Leave balances, long service leave history, employee records, pay rates and agreement configuration. Year-to-date gross, tax and super stay in the old system, which finalises them.

What does the employee see in myGov?

Two income statement lines for the financial year, both marked tax ready. It is the same experience as changing jobs part-way through a year, and their tax return combines the two.

Where do the old year-to-date figures live after the switch?

In the outgoing system's finalised reporting, and, for convenience, in a payslip notes section on the first pay run in the new system so the crew can see their prior totals without ringing the office.

Why do pay categories cause a problem on carryover?

Because the old system's categories rarely map one-to-one to the new ones, especially on super application. Load year-to-date figures against a category that treats super differently and the super calculation base for the year no longer agrees with what was actually paid.

Reviewed August 2026. General information, not legal or tax advice.

Next step

Not sure which option fits your cutover date?

Tell us when you want to switch and what you're on now. We'll tell you whether a fresh start or a carryover is cleaner for your year.

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