Modern Slavery offences are, most of the time, committed across several national and international jurisdictions. Investigating the criminality committed in the UK and providing the assistance necessary to the potential victims is fundamental for the UK agencies but so is engaging early, on a police-to-police basis, with the partners from the countries of origin and transit. This is essential not only with the view to checking the information received and corroborating evidence to strengthen prosecution in the UK but also because, essentially, the first stages of the human trafficking process take place in a foreign jurisdiction and very often involves other members of the organised crime group, thus requiring a concerted effort in order to dismantling the entire criminal enterprise.