We would like to perform update of specific fields from our HR system into concur. There are 1-2 fields that I would like to update using 305 import file. 

Do i need to input all of the required fields in the 305 import file (there are like 10 of them) or can I just provide only the fields to be updated. 

for example, Locale Code, Country code, Currency code are all required fields in the 305 record, but I need to update only the approval manager (or email id). In such a scenario, can i pass the 100 record with 'UPDATE' (Update the existing record with only those fields that are non-blank in the import file) and then pass 305 with my employee number and email id/ Manager id? Would concur system accept such an input?