Hi,
The basis for whether VAT is to be charged in a particular situation depend on the place of supply rules.
If a UK solicitor is making a supply of legal services and the customer belongs overseas then VAT would not be charged as it would be considered outside the scope of VAT.
If the legal services are supplied to a customer who belongs in the UK then VAT would need to be charged. However, if the legal services are related to land and the land is in the UK then VAT would have to be charged regardless of where the customer belongs. You can see guidance here:
Land related services
B2C services of a professional, technical, financial, intellectual or other intangible nature supplied to customers outside the UK
If the person to whom the supplies are being made changes and the place of belonging changes this could have an effect on the liability of the solicitor's supplies.
Any adjustments, and, or repayments of VAT for this would need to be arranged by the solicitor.
Thank you.