GST is charged by Bluethumb on the commission and freight collected by Bluethumb, and not on the money collected for the supply of the art. 

Where you are registered for GST and have provided Bluethumb with a registered ABN, Bluethumb will collect the GST for the supply of art on your behalf, and issue the appropriate sales invoice to the purchaser. 

Every time you sell something you will be provided with a copy of the sales invoice and a Bluethumb tax invoice for commission and freight collected via email. These emails contain the information you need to complete your tax return. 

Bluethumb does not issue a summary of totals earned during the last financial year or send out a summary of artist payments. You will need to keep your own records during the year.