Hello, A magazine company agrees to place an advert for a client at a cost of say £100 a month for 12 months, the client pays the company each month. Part way through this contract the magazine company becomes VAT registered, can they start to charge VAT on top of the £100 to the client or must they make the total up to be £100 still inc VAT? The client is not VAT registered and so is not keen on now having to pay the extra VAT themselves. There was no mention of VAT either being excluded or included at the beginning of the contract. Thanks.