Supplier/Parent Company Question

We are trying to clean up our vendor records and are coming across many vendors with the same Tax ID with different names. Many of them are parent/sub relationships. My question is, if you enter the Tax ID at the parent and leave the sub 1099 blank for a is 1099 reportable, will the 1099 run pick up the sub company and add it to the parent companies 1099? Is there a user guide or best practices area I can go to for the best ways to set up our records? Thank you for your help.