Partial shipping means that we are shipping the oligos you ordered to you as they are completed rather than our default method of waiting to ship until the order is complete---with all of the oligos shipping at the same time.
We make every effort to synthesize and ship your oligos as quickly as possible because we know that they are time sensitive. On occasion one or more oligos may become delayed because they did not pass one of our quality control checks, or their processing took longer than anticipated. In these cases we can ship you a partial order, if you would like to have the order set that way. You can also choose to have your order ship partial if you know some of your oligos will take longer than others (because of purification, etc.), which will incur an extra shipping charge. If you would like to set an order to ship partial, you can request it at the time of checkout or contact IDT Customer Care.