Résumé : In this paper, we attempt to apply Graeber’s model of “baseline communism” to a medieval financial custom that was widespread in the former Low Countries: the Inliggen custom. This custom implied that a well-off debtor (often a high aristocrat) could send pledges (often his vassals and councillors) in an inn, to remain hostages as long as his creditor was not reimbursed. Inns offered far more than just lodging facilities, and providing food and drinks; they were information hubs, providing the guest with banking services, brokerage facilities and commercial storage, hence, their intimate relationship to medieval bankers such as the Piedmontese moneylenders. Within the institutional framework of the Inliggen custom, the inn was at the centre of a social network linking the creditor, the debtor and his pledges and the hosteller. Bearing close resemblance to the Pilgrimage economy of the late Middle Ages, the sojourn of hostages in an inn as pledges had a positive impact on the urban economy: the pledges were supposed to eat, drink and sleep in a high-standing inn, following the patterns of a conspicuous consumption, the town administration levied fruitful taxes on the wine excises and the pledges could also entertain ties with the local merchants aiming at buying luxury products such as clothes or jewels.All in all, elements of a “baseline communism” surfaced within this extended credit network: the loaned capital often fuelled the urgent needs of a high aristocrat; the practice both relied on the hospitality custom and on the collective solidarity of the pledges for their overlord. Finally, the ambiguous position of the hosteller (host, broker and partner of the Piedmontese moneylenders) shows that the financial custom was a by-product of aggressive profit-seeking strategies for both the lenders and the hostellers. In this sense, and as recognised by Graeber himself, it was no naïve communism but rather a crucial component of the exchanges in a highly commercialised urban society. Ultimately, this custom could be viewed as a primitive contract-enforcement mechanism (CEM). But to prove its efficiency we need to collect a broader sample of quantitative data that is not easily available for the time span of our study.