The group, which is owned by Swiss luxury conglomerate Richemont, made a £27m loss in the year to 31 March 2012 compared with a 5.2m profit the previous year.
According to filings on Companies House it spent £22.9m on building new automated distribution centres in the US and Hong Kong and London.
In November 2011 Net-A-Porter made its first major foray into China with the £6.6m acquisition of Shouke, the discount online retailer, which it relaunched as the Outnet in March 2012.
Net-A-Porter’s total revenue jumped 55 per cent to £368m on £238m the previous year, boosted in part by a full year’s trading for Mr Porter – its recently launched male equivalent website.
The group warned it faced increasing competition from traditional retailers ramping up their online activities.