Charging Differnt Postage Costs To Northern Ireland

[Dan1980]

So, the courier I use it charging me a lot more to ship to Northern Ireland but I have been charging people the same amount as I would an order to shipped to England. I can see under the UK shipping rule you can untick Northern Ireland, meaning now I don't ship there.

How do I now add Northern Ireland as an option but increase the postage or change the service?

I thought about an additional shipping rate, adding in the UK and leaving only Northern Ireland ticked and setting a rate this way but it will not allow me to do that. 

Please help!!