If one forgets and has missed the year, and also faces financial or other constraints in making the payment, is it permissible to postpone zakat payment?

It should be understood that the basic obligation of zakat payment must be carried out promptly. However, in situations as mentioned above, there are two possible solutions:

1. 1. Pay zakat in installments until the full amount is completed.
2. 2. If unable to do so, it may be postponed with the intention to fulfill it in the following year.
3.  

Nevertheless, it is preferable to settle the payment immediately, as it is considered a debt and an obligation to Allah SWT as well as to the eligible recipients (asnaf).

Reference: Resolution 1, Compilation of Shariah Queries LZS January 2019 – June 2019, Approved by the Meeting of the Shariah Advisory Committee of LZS.