How can I access county list for company address - mine is not recognised and therefore I cannot pull through a VAT code for sales invoicing

You're unable to access the county list, Eannerussell.

You'll have to create the county VAT manually. This way, it will show on your invoice.

I'll guide you how:

1. Click Taxes.
2. Go to VAT.
3. Click Add tax, then select Tax rate.
4. Enter a desired name in the Tax name field.
5. Tick the Sales box, then enter the tax rate.
6. Select the account.
7. Set up how you want to show the tax and net amounts on the return lines. 
8. Click Save.

When you create an invoice, select the county VAT you've created.

This will also be reported on the VAT return. 

I'll also share the common VAT codes as additional reference. 

If you have other VAT concerns, the Community is open 24/7 to help you.