Is Zakat obligatory on the pension salary deposited in the bank account of the children and wife, inherited from the deceased father, and what about the Zakat for past years that has not been paid?

Zakat is obligatory on the retirement salary balance if it reaches the nisab and a hawl (one lunar year) passes over it. The nisab is equivalent to 595 grams of silver. It should be considered whether each individual's share reached the nisab or if it's the total balance, based on the differing opinions regarding the effect of commingling funds. Zakat does not lapse with the passage of time, so it must be paid for past years, along with repentance for the delay.