HMRC has recently updated its guidance on the VAT treatment of direct marketing, including posting or arranging the posting of publicity material to customers. This includes door drops.
HMRC’s view is that supplies of printed materials that are combined with other services such as marketing should be categorised as a single supply of standard rated direct marketing services. Such services would previously have been treated as a single supply of zero rated services.
You can find out more information in R&C Brief 10 (2015).
In light of this update, you should ensure that standard rated VAT is accounted for on any direct marketing services you perform on behalf of your clients from 1 August 2015 onwards.