In the end we had to opt for the same solution recommended by DizzyLizzy (ShipZip - thanks to DizzyLizzy for this). It has opened our eyes to how much more functionality that's Standard on other platforms is missing from Shopify: order cut offs, orde...

I'm guessing there's still no fix for this, right? Postcode delivery zones come as standard on WordPress with Woo Commerce, you know.