The Government is expected to raise £40m from research after Mifid II through VAT, according to the OBR.
Currently, VAT is charged at the standard rate for advice or recommendations, whereas charges for arranging a sale is exempt from the tax.
Research was not previously subject to VAT when it was bundled with execution costs.
HMRC has been consulting with the industry, including the Investment Association, regarding the VAT implications of Mifid II.
The OBR fiscal and economic outlook, which was released in tandem with the Autumn Budget, says the Government can expect to raise £40m annually from the next financial year, rising to £45m in 2021/22.