Does Zendesk Support have an API input/import tool to import data from another program or format such as CSV or Excel?
No, Zendesk does not have prebuilt input or import functionality with our API to communicate with third party systems for data import and creation. We recommend writing a custom script or program to bridge communication between your tool(s) and Zendesk Support.
Please see the following quote by one of our Product Managers found here.
"Due to the amount of different data from an external system can take, it becomes difficult to make one solution that fits all. As a result, we'd have to come up with some sort of CSV structure to conform to. This means the burden is put back on you, having to augment all the data to our CSV structure which could mean losing data in some cases or frustration if the CSV structure isn't right and Zendesk rejects it."