Hi.If there is no VAT registration number on the quote, then its reasonable for the customer to assume that the price is the price he or she will pay. If the VAT registration number is ***** on the quote, it should make it clear whether the quoted price is VAT inclusive or VAT exclusive. The trader can certainly try to add VAT when the job is done but from the experience of others, the customer is in the clear if they refuse to pay the VAT and the trader will have to treat the price as VAT inclusive and take the hit himself.This is really more of a legal question and, therefore, it can be a minefield. The section on misleading omissions in The Consumer Protection from Unfair Trading Regulations 2008 here and The Consumer Protection Act 1987 (see section 21 (1) (a)) here may provide some protection to a customer where it is not clear that VAT will be added to a quoted price. You might also look under the heading "Prices in advertisements, catalogues and price lists" here.I hope this helps but let me know if you have any further questions.