Applying Gift Cards on the PS4

I got a gift card for the PS4.

I was wondering, when I use the code for one account, if it would also be available to other accounts on my PS4?

If by Gift Card you are referring to Prepaid cards to top up your wallet, then unless the other accounts can buy though another account, the answer is generally no.

Prepaid cards add funds to a PlayStation Network Account which is actually independent from any console as you can access your PlayStation Network account though the browser and buy stuff that way.

When you say,

other accounts on my ps4

I am assuming that you are referring to the associated PlayStation Network Accounts which would have their own Wallets with their own funds and generally are independent from each other.

An exception to this is using Family Accounts where the Child Family Member Accounts can spend money from the Family Manager account.

Children and teenagers can spend funds from the family manager's wallet within a spending limit set by the family manager, but only when enough funds are available.

However, once these accounts are detected to have turned 18, they graduate to Adult Family Members and are then unable to spend funds from the wallet of the Family Manager. This trade off is probably due to the fact that Child Family Member Accounts cannot add funds to their wallets whereas Adult Family Member accounts can and can also leave the Family Account (although they lose access to shared content).

Any family members over the age of 18 have full unrestricted access to PlayStation Network on their account, as well as their own wallet for purchases from PlayStation Store. However, they can’t add members to the family or set parental controls for children if they haven't been made a parent or guardian by the family manager. An adult user can choose to leave the family at any time, but this will affect any content shared within the family.

If however, this gift card is part of a free game giveaway, then even if an account isn't part of the Family, it can still access the game on any that it shares with that account.