Generally, debt due refers to an obligation which is due, that is, mature. Within the meaning of a garnishment statute, a debt is due and therefore subject to a garnishment when there is an existing obligation to pay in the present or in the future.
The process of garnishment lies as incident to an action when a debt is due from any person to the defendant and that from the time of leaving the copy of the process with the garnishee any debt due from him/her to the defendant, should be secured in the hands of such garnishee to pay such judgment as the plaintiff may recover.
Under some jurisdictions, in order to be due, a debt need not be presently payable. Nor need it be liquidated. Nor will the fact that the debt may be defeated by a condition subsequent put it beyond the reach of garnishment. [Calechman v. Great Atl. & Pac. Tea Co., 120 Conn. 265 (Conn. 1935)].