A combination: the employment contract and any amendments, assignment or secondment letters, payslips and tax or social insurance records for each period, contemporaneous organisation charts, and statements from managers who supervised the work. No single document usually covers a history spread across several affiliates.
Retrieve from the source, early
Records held by an affiliate abroad often sit with a payroll provider or an archive rather than with the current human resources team, and translation may be needed. Send requests before drafting begins and record who was asked and when. Where a document cannot be produced, obtain a written explanation and a statement from someone with direct knowledge, rather than leaving an unexplained gap in the chronology.
Build the evidence set segment by segment rather than as a single pile: employment contract and amendments, assignment or secondment letters, payslips, tax or social insurance records, contemporaneous organisation charts, and statements from managers who supervised the work. No single document usually covers a history spread across several affiliates, and the gaps become visible only when the records are laid against the chronology. Records held abroad often sit with a payroll provider or an archive rather than with the current human resources team, and translation adds time.
Where a document cannot be produced, obtain a written explanation and a statement from someone with direct knowledge. Log every request and reply with dates.