Even in relation to the history of documentation – given its nature as legal history, social history, history of institutions and ideas – we encounter the theme of frontiers, since the latter is inseparable from that of exchanges. From the beginning of the ninth century, when Europe was, economically and politically, Carolingian, cultural ties (and thus also the circulation of documentary models) were always assumed to have been active from the Frankish area to the newly-conquered regions. Lombard Italy, as one of the many Urkundenlandschaften of the Empire, does not appear to have been an exception. If the changes to written instruments (diplomas and notitiae iudicati) directly instrumental to political communication from the top, as well as dispute resolution according to the scheme of the placitum, were evident and nearly immediate, even the composite panorama of private charters began to be standardised and typified and the inclusion of ruling elites from across the Alps established in the peninsula a legal pluralism previously unknown. The aim of this contribution is to evaluate the rhythms of that change, their form and importance and, in particular, the areas to which they refer, and the possible maintenance – in terms of creation and/or consolidation –, in the face of the new Carolingian koinè, of “borders” internal to the kingdom. Leaving aside all the constraints placed on this research by sources with diverse structures among the various territorial sets, such a plurality of situations must be evaluated from the degree of penetration of the imported material, and of the response models of traditional documentary cultures, thus assigning the right value to the undoubted peculiarities, without giving up on the verification of crossovers between environments which are very clearly far from impermeable.