Does zakat become due on the الضمان amounts (for residency, electricity, and house rent) that cannot be disposed of except after canceling the services, knowing that they have reached the nisab? And if it is not due now, will it become due upon their retrieval, and how should it be paid: immediately upon receipt or after a full year has passed since their possession, and is it permissible to pay zakat on them voluntarily?

The funds an individual pays as cash deposits—held by the entity they are dealing with—are not subject to zakat (definition), due to incomplete ownership. The individual does not have full power to dispose of them, and thus they resemble frozen assets.

If these cash deposits are returned to their owner, it is preferable to pay zakat on them for one year from the time of receipt. There is no sin upon him if he delays paying zakat until a full year has passed since their receipt.

As for donating these funds voluntarily as charity, that is a permissible act.