No fee is charged for the quota increase itself. Actual consumption exceeding the volume under your active subscription is billable on a separate basis as per the pricing policy.
Note
For educational and open-source projects, you can increase public repository quotas for free by contacting support.
In the left-hand panel, select Organizations and open the organization.
Under Usage and billing, navigate to Quotas.
On the Usage quotas page, select the following tab:
CI/CD: For CI process runtime in private repositories.
Git: For storage capacity of private repositories and LFS.
In the card with the quota you need, click Change.
In the Change quota window, set the new value. Specify the final quota, not the value to increase your quota by, e.g., specify 3100 to add 100 minutes to the CI runtime quota of 3,000 minutes.
Click Update quota.
The new value applies immediately and appears in the quota card.