One of the Charleston region’s largest credit unions is upgrading its online banking system, requiring it to disable the service for about a day.

South Carolina Federal Credit Union said the option would not be available starting at 11 a.m. Monday. The new system is expected to be activated by 3 p.m. on Tuesday, according to a notice the lender sent to customers.

The upgrade does not affect ATMs or telephone banking.

The North Charleston-based credit union sent customer instructions for logging into the new system. A new app will be required for Apple and Android phones and tablets.

The credit union is directing customers to for details.

Contact John McDermott at 937-5572.