The original author of the forum post.    coreperformance 
I have multiple vendors, and I need them to be able to enter orders for their customers, without paying through Catalook.  I tried making a price rule that made their products free to them if they were logged in.  This does not work because as they change the customer's name and address, it changes the vendor profile to that name and address.  Every order they place gets assigned to the most recent cusomer they enter.

I tried creating a large coupon that would cover the cost of any single order.  Except that if the amount in the cart is negative, it still wants payment info (unlike a cart with a 0 total).  I thought I could fix this with a price rule (if amount in cart is less than 0, make the cart amount 0) but you can't make a rule for cart total, only quantity (right?)

I need a coupon that will allow vendors to enter orders for various cutomers without being charged.  A 100% off coupon.

Is this the only way to accomplish this?  Is there a simpler solution I have not thought of?

Admin users can add orders on behalf of customers:
Module CAT_Customers (CATALooK.netStore -> Customers) ->  search for a user -> click on the 'Login' link in the 'Change User' column -> add products to cart and checkout.

You could select another payment type from the [Store payment types] selector on module CAT_StoreSettings (CATALooK.netStore -> Store Settings) e.g. 'Cash in Advance' and use this to checkout w/o paying. 

Since the v05.04.03 you can also setup cart related coupon codes:
Module CAT_PriceRules (CATALooK.netStore -> Price Rules) -> Add Cart Price Rules -> [Description} = 'Vendor Coupon'; [Price Rule Item] = (This item will be inserted with the price calculated by the formula. You can select any product or create a special product to use it as coupon code. To make this special product not orderable from the product lists, choose [Not Publish (Disabled)/Coupon] and / or [Status(kind of use)] = Bundled/Coupon in module CAT_Products for this item.); [Formula] = -100% or [Formula] = 0; [Coupon Codes] = Coupon Codes (Press ENTER/CR to separate).
Module CAT_Cart -> select [View Options] from the module menu -> turn on the [Use advanced coupon management] option