Hi Jason,
Unfortunately, there is no way around this when using multiple Shopify locations. When more than one location is called upon to satisfy an order, Shopify will charge per location and blend the rates.
The reasoning behind this process is that it is (in theory) costing you extra to ship because it is assumed you’re shipping the order from multiple locations. Of course, in reality, as is clear from your situation, that isn’t always the situation.
The only way to avoid this is to have all of your inventory in one location. Based on what you’ve described this might be possible, since the “house” locations are close by and only serve to warehouse excess inventory. However if you absolutely need to have inventory tracked in Shopify by location, there is unfortunately no workaround that I’m aware of.
Even if you use a third-party rate calculator like Intuitive Shipping, the issue would still exist. That’s because Shopify always splits the order into sub-carts for each location, sends the info to our system, we calculate the rate per sub-cart and send it back to Shopify, they blend each sub-cart calculation into a single combined rate at checkout.
Best regards,
Ron