VAN ERP/VAN VLIET build ng To answer the question whether the right of retention works against third parties with a real right on the object we should distinguish between movable and immovable property and the question whether the real right is older or younger than the right of retention A right of retention on movables or immovables works against the holder of a prior interest over the object pov ided either that the holder of the prior interest allowed the debtor to enter into the contract in which the non-perfomance takes place or that the creditor/retentor assumed in good faith that the debtor was so entitled(art. 3: 291(2)CC). The right of retention of mova bles also works a ga inst interests subsequently created(art. 3: 291(1)CC). As a right of retention over immovable property is not always recognizable to third parties (it cannot be registered onto the and register) the right does not work aga inst every holder of a younger interest. It does so only if the retentor exercises his power over the object in a way which is recognizable to third parties(e.g. name plate on the fence). However, even if the power is not recognizable to outsiders, the right of retention works against a third party who knows of the right of retention. See the judgments in Deen/Van der Drift and winters/Kantoor vande Toekomst Set-off( verrekening’) he debtor of a cla im who has a counter-ch im aga inst his creditor may set off his debt aga inst his claim by unila teral declaration in any form(art. 6: 127(1)CC).Where the parties have a greed set-off beforehand, e.g. in a relationship of current account, claims are automatically set off (art. 6: 140 CC). Set-off requires that the caim and counter-clam are between the same parties and that both claims are similar in ontent. Moreover, to be able to set off a debtor should already be entitled to perform his obligation and should be able to force the other party to perfom his counter-obligation(art. 6: 127(2)CC). He cannot enforce payment from his counter-party if the atter has a right to suspend performance, if the payment is not yet due, or if the counter-obligation is a natural obligation(obligatio naturalis) Set-off will cause the obligations to fall away to their common amount. Although the result is to some extent similarto payment it should not be considered as such Assignment of the claim does not deprive the debtor of this claim of his right to set off, prov ided that both this claim and the debtor's counter-chim arose from the same legal relationship, or that the debtor's counter-claim arose to him and became due before the assignment(art. 6: 130(1)CC) Once the possibility of set-off has emerged, it cannot lapse as a result of extinctive prescription. Set-off remains possible although the counter-claim has turned into a mere naturalobligation due to prescription(art. 6: 131(1)CC) The requirements of set-off are more lenient in the creditors insolvency. It is not See B Wessels(ed), Verrekenng, Kluwer, Deventer 1996, WAK Rank, Verrekening door de bank als oneigenlijke zekerhed, Nederlands Instituut voor het Bank- en Effectenrecht Amsterdam 1990; AS Hartkamp, Assers Handleidng tot de beoefening van het Nederlands burgerlijk recht, vol 4 L Verbntenissenrecht, De verbintens n het algemeen, Ilth ed, Zwolle 2000VAN ERP/VAN VLIET 10 building. To answer the question whether the right of retention works against third parties with a real right on the object we should distinguish between movable and immovable property and the question whether the real right is older or younger than the right of retention. A right of retention on movables or immovables works against the holder of a prior interest over the object provided either that the holder of the prior interest allowed the debtor to enter into the contract in which the non-performance takes place or that the creditor/retentor assumed in good faith that the debtor was so entitled (art. 3:291(2) CC). The right of retention of movables also works against interests subsequently created (art. 3:291(1) CC). As a right of retention over immovable property is not always recognizable to third parties (it cannot be registered onto the land register) the right does not work against every holder of a younger interest. It does so only if the retentor exercises his power over the object in a way which is recognizable to third parties (e.g. name plate on the fence). However, even if the power is not recognizable to outsiders, the right of retention works against a third party who knows of the right of retention. See the judgments in Deen/Van der Drift and Winters/Kantoor van de Toekomst. 6 Set-off (‘verrekening’)41 The debtor of a claim who has a counter-claim against his creditor may set off his debt against his claim by unilateral declaration in any form (art. 6:127(1) CC). Where the parties have agreed set-off beforehand, e.g. in a relationship of current account, claims are automatically set off (art. 6:140 CC). Set-off requires that the claim and counter-claim are between the same parties and that both claims are similar in content. Moreover, to be able to set off a debtor should already be entitled to perform his obligation and should be able to force the other party to perform his counter-obligation (art. 6:127(2) CC). He cannot enforce payment from his counter-party if the latter has a right to suspend performance, if the payment is not yet due, or if the counter-obligation is a natural obligation (obligatio naturalis). Set-off will cause the obligations to fall away to their common amount. Although the result is to some extent similar to payment it should not be considered as such. Assignment of the claim does not deprive the debtor of this claim of his right to set off, provided that both this claim and the debtor’s counter-claim arose from the same legal relationship, or that the debtor's counter-claim arose to him and became due before the assignment (art. 6:130(1) CC). Once the possibility of set-off has emerged, it cannot lapse as a result of extinctive prescription. Set-off remains possible although the counter-claim has turned into a mere natural obligation due to prescription (art. 6:131(1) CC). The requirements of set-off are more lenient in the creditor's insolvency. It is not 41. See B. Wessels (ed.), Verrekening, Kluwer, Deventer 1996; W.A.K. Rank, Verrekening door de bank als oneigenlijke zekerheid, Nederlands Instituut voor het Bank- en Effectenrecht, Amsterdam 1990; A.S. Hartkamp, Asser’s Handleiding tot de beoefening van het Nederlands burgerlijk recht, vol. 4 I, Verbintenissenrecht, De verbintenis in het algemeen, 11th ed., Zwolle 2000, ch. 12