Create Customer SD_CUSTOMER_MAINTAIN_ALL or CMD_EI_API

Hi,

I'm trying to create a function that makes it possible to create customers like in XD01.

I read in the forum that the function module SD_CUSTOMER_MAINTAIN_ALL shouldn't be used for that.

Is that correct?

I read also that I should use the Class CMD_EI_API with method MAINTAIN_BAPI. But when I try to create a customer I get the error: Mandatory partner role is missing for sales area 0003 01 05

Does anybody knwo what I'm missing in here?

Best regards,

Dennis