How does dual criminality affect whether a foreign investigation can obtain evidence from my jurisdiction?

Dual criminality requires that the conduct under investigation constitutes a criminal offence in both the requesting and executing states. Many jurisdictions apply this strictly—if the alleged conduct is lawful where you reside, cooperation may be refused. However, some treaties and domestic laws permit flexible interpretation, focusing on underlying conduct rather than precise legal classification. Tax-related requests often face dual criminality challenges, as definitions of tax evasion versus avoidance differ significantly. Courts typically assess criminality at the time of the request, not when the conduct allegedly occurred.