Product Surcharge based on product and location - UK markets

[kev-superrb]

In August, Scotland are introducing an Environmental Deposit scheme on single use cans and bottles - both of which my client sells.

I have looked at a number of apps which have been mentioned on similar questions for other countries/regions but unfortunately these are either fees for all customers or use geoIP to identify the customers' location.

GeoIP is not an option due to how unreliable it is as best these days and the fee being charged is a legal obligation.

I need to be able to achieve the following and hoping somebody might have some thoughts, suggestions or insight -

1. Fee is only shown to customers shipping the item to Scotland
   • Believe this would need to be triggered by the shipping address in the checkout which would require Shopify Plus?
2. The fee is detailed out as a stand-alone line item in the order overview
3. The fee needs to be applied only to certain products
   • Due to the surcharge being per can or bottle and my client selling a 6 pack as one product for example, we potentially need a way to create different pack size charges which we can attribute to the relevant products.
   • So a 6 pack would have a surcharge fee of £1.20 (the fee is £0.20 per can or bottle) and a 12 pack would have a surcharge fee of £2.40
4. If the fee is added, the customer cannot remove it

The UpCharge: Surcharges app comes very close to ticking all the boxes but the location functionality is geoIP based.

Any thoughts or ideas much appreciated