ou calendrier de paiements échelonnés mis en place ...

serait une autre possibilité.

Exemple :
Paiement échelonné - Glastint
www.glastint.com/paiement-echelonne.php -

Profitez de facilités de paiement. Les Centres Glastint peuvent vous proposer des solutions d'échelonnement des paiements pour l'équipement de votre ...


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Note added at 21 hrs (2012-01-19 18:28:07 GMT)
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Versement(s) partiel(s) pour aller dans le sens de Francoise ?

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Note added at 21 hrs (2012-01-19 18:34:25 GMT)
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Il s'agirait bien d'une série de paiements:
installment contract n. an agreement in which payments of money, delivery of goods or performance of services are to be made in a series of payments, deliveries or performances, usually on specific dates or upon certain happenings. One significance is that failure to pay an installment when due is a breach in which damages can be assessed based on the portion which has not been paid, and is an excuse for the other party not to perform further. In many installment contracts, failure to make a payment gives the seller of an article the right to repossess (take it back). (the free dictionary)