What to consider prior to determining whether to use an intervention: matters to consider when looking at particular types of taxable person or activity: box breaking and box consolidation: issues to consider: has there been a supply for VAT
You should read VATF34000.
It is essential that you confirm that a transaction falls within the scope of VAT before moving to second-level questions looking at other issues.
In relation to box breaking, it will be particularly important to consider conditions 3 and 4, as explained in VATF34200 and set out below.
it is made by a taxable person (someone who is, or is required to be registered); and
it is made in the course or furtherance of any business carried on or to be carried on by that person.
If phones are being purchased by individuals who are not employees or agents of the box breaker or box consolidator, the individual may not be a taxable person and hence their supply to the box breaker or box consolidator would be outside the scope of VAT. However, you need to carefully consider the guidance on agency before reaching a decision on this point (VATF36232).