Will the veteran's payments always be paid to the same company?

No. It is common practice in the mortgage lending industry to sell mortgages, often before the first payment is even due. If your loan is sold, you may find that you sent your first payment to the wrong place and the new holder of your loan may send you an overdue notice. Even though you know you made the payment, and is is up to the two lenders to get it straightened out, do not ignore the notice. (Most lenders will notify the veteran if the loan is sold and help straighten out any problems.)