General rule: Supplies received wholly for private purposes
If a supply of services is made to a relevant business customer who will use it wholly for their own private use or the private use of their staff, then the supply will be treated as a B2C supply.
For example, a VAT registered builder may send a domestic appliance - that is not used in his business - away for repair. This would be regarded as wholly for a private purpose.
A company, charity, or government body cannot act in a private capacity.