Solar panels are being installed on commercial premises (non residential) owned by a client. The installer has charged VAT at 5%; I thought this only applied to residential premises (see VAT Notice 708/6). I have also noted that they applied the same rate to an installation 3 years ago. Before I point this out to the client and start the whole hassle of obtaining correct invoices and arguing the toss with the supplier, can anybody confirm that I am right that it should be 20%? Let me know if more detail is required.