Civil Law
Updated 29th May 2025
Onerous
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"Onerous" is used to describe something that is burdensome or disadvantageous, particularly in the context of a debtor's obligations.

Meaning of Onerous

In the context of multiple debts owed by a debtor, an "onerous" debt is considered more burdensome to the debtor. This concept is primarily relevant in determining the application of payments when a debtor owes several debts of the same kind to the same creditor.

Application of Payments

When a debtor has several debts that are due and are not of the same nature and burden, the payment is applied to the most onerous debt. If the debts are of the same nature and burden, payment is applied proportionately.

Examples of Onerous Debts

  • A debt secured by a mortgage is more onerous than a simple, unsecured obligation.
  • When a person owes two debts, one as a sole debtor and another as a solidary co-debtor, the latter is considered more onerous as regards the principal debt.
  • A guaranteed debt is more onerous than an unsecured debt.

The determination of which obligation is most onerous can sometimes be difficult and depends on the particular circumstances of the case.