Indebtedness in Islam is not just about monetary or any other material loan. It can also be spiritual, or moral. Each of these is considered a problem for which Islam proffers a solution.
In the spiritual realm, a Muslim may become a debtor when he skips certain daily prayers (Salat). And, until he observes such prayers, no matter how late, he remains a spiritual debtor.
He may also become a debtor when he misses some days of fasting in Ramadan for whatever reason or when he fails to pay Zakah at the appropriate time.
Also, his refusal to perform Hajj when he is capable of doing so may amount to indebtedness. In each of these cases, the only rectification which amounts to payment of debt is to atone for the omission.
Such rectification can be made by the debtor himself or by someone else (in the case of Zakah and hajj). As for Salat the rule is different.
No other person can help to pay any debt incurred by you if you deliberately failed to observe Salat at its right time.
The payment must be done by the very person who incurred the debt. It must be remembered that there ca be no excuse for missing Salat consistently.
In the case of fasting, there is a temporary indebtedness and there is a permanent one. An example of a temporary indebtedness is that of a menstruating woman or a wayfarer or a sick person.
Each of them is to rectify the omission by himself/herself when Ramadan is over and the situation becomes normal.
But a person who is unable to fast due to old age or permanent ailment is not expected to fast after Ramadan.
What he has to do is feeding one indigent person each day of Ramadan for 30 or 29 days as the case may be. That is permanent indebtedness.
Other areas of indebtedness in Islam include Zakah and Hajj. Zakah can be paid on behalf of the estate owner either by his offspring or the beneficiaries of his legacy.
This can happen posthumously or if the principal turns infamy. Hajj, on the other hand, can only be performed by proxy if disability prevents the person concerned from going through its rigour or he is unable to perform that function till his death.
Any good Muslim from among his children, relatives or friends can do it on his behalf. Please continue tomorrow. Ramadan Karim!