Thank you, this has helped, looking at the customer relationship, they are registered as a separate entity, there isn't a link to indicate that they're part of a Branch. So we'll let them know the UK VAT has been charged correctly.
We have charged UK VAT on an export, the customer is challenging this, as we have shipped the goods to an office they have in the EU, however they want us to invoice the UK.
This is a B2B transaction for Goods and services (Services relate to work carried out on equipment prior to it being exported).
Should we credit the VAT, as we have proof the goods have been exported, or should we stand out ground and leave the VAT charge on the invoice?