Starting under materially different terms before the position is confirmed carries real risk, and filing an application does not itself authorize work under a new arrangement. Ask the employer to hold the effective date rather than starting and correcting afterwards.
Effective dates are negotiable; a record is not
Employers often set an effective date for administrative convenience and can move it once they understand why. Explain that the change touches the professional's status, not only payroll, and propose a date after the review. Where the employer genuinely cannot wait, counsel should know that constraint at the outset so the sequence, including any new application, can be planned around it.
Verbal estimates from a front counter shift; a written date from the registrar gives the employer something to plan around. Plan on two passes rather than one: the translation arrives, it is read against the listing and the employer letter, and something is adjusted. If the employer changes the role during preparation, reassess the case rather than submit a description known to be outdated. Ask the US employer whether the start can move if the listed-profession qualification or prior experience remains unproven. The practical choice is whether the record is ready for inspection or requires the employer’s petition route first.