Quick question. Creating a Sales Order from SuiteScript and I'm getting a DUP_RCRD error. I'm not setting an externalid and the tranid is set to autogenerate. Does anyone know what the cause might be?

Can you post your code?

That error usually means something in the record is creating a duplicate reference even if externalid and tranid are not set. Please check if the script or another process is trying to create the same order twice or if there is a unique field like a custom external id being reused.

The script works for some Customers, but not others. It only creates a basic sales order with a single item (for later processing).

If it only fails for certain customers, there might be a duplicate transaction already tied to that customer. Try checking if a pending or identical Sales Order exists for them, since NetSuite can block new ones with matching references or identical data.