Will SSIS know which of the columns is missing?The answer is no.But if you know that there is a rule such as: if there are four columns in a row, add a fifth as Col1 and set its value to NULL, that can be done.I am going to sign off now, by saying that if you can come up with the necessary logical steps to process your file (and I do not think that you are there yet), it will be possible to implement