Discover is well aware of the fact that some people will use their whole limit. As a side effect they will consider how much over they will allow you to go. If a charge causes 0.82 over most banks do not blink an eye and just pay the cents. Having the charge decline makes the bank look petty unless it is by a significant amount. Be aware that banks will use a number of processes to manage their cards. Some banks have over the limit fees that are in your contract and will be charged. Some accounts have no preset card limit such as most Signature, Infinite, World, and World Elite cards. With no preset limit the charges are at the banks discretion so they will go transaction by transaction once the limit is met. Outside that banks use the limit as either a hard limit where anything except ~$5 or so over is stopped. Only debit cards and very petty banks use the limit as a super hard stop. Lastly any amount over the limit is due by the due date regardless of how much it is so you will be required to be in your limit by then.
