This article explains how the card limits work when creating a card
When creating a card you are required to set a card limit. This is the maximum amount that can be spent on the card, provided sufficient funds are available in the associated funding account.
The balance remains in your funding account and is not transferred to the card, although it will be ringfenced for a specific transaction as soon as the card is successfully authorised.
If a merchant attempts to charge the card for more than the limits you've set, the authorisation will decline. Learn how to schedule limit changes here.
These card limits are different to the card velocity limits set by the card issuers. The lower of the two limits will apply when making card payments.