Once you have purchased your job posting credits, your job credit bank balance (located under your account page, bottom left) will be updated and reflect the new job posting credits. You will see something similar to the image below.

These credits can be used at any time (one credit per post) and do not expire, so you may use them as and when you require. To save, why not purchase a larger number of credits and load up your job credit bank.

When posting a job you are given the choice of using one of your available credits from your bank or purchasing more. If you choose to use one of the available credits the balance will reflect the withdrawal after the transaction is completed.