When searching for registered designs, one must remember that designs can be registered with national, regional or international design offices.
National Intellectual Property Offices
National design registration offices such as the UK IPO and the Benelux Office for Intellectual Property contain all UK and Benelux Registered Designs that have been applied for and registered in the UK and Benelux respectively. You can search this database by class, number, product or proprietor.
http://www.ipo.gov.uk and https://register.boip.int/ds-online-web/?l=en
Office for Harmonisation of the Internal Market (OHIM)
To protect your design throughout the EU, one can apply for a Registered Community Design (RCD) at OHIM and will offer protection across all 27 Member States.
The OHIM database contains all RCDs which have been applied for via OHIM. It does not, however, hold details of registered designs which were applied for internationally via WIPO and which designate the EU as the contracting state (see below). Like the UK IPO, you can search the OHIM database by class, number, indication of product or proprietor, as well as by filing date.
World Intellectual Property Office (WIPO)
The Hague Agreement for the International Registration of Industrial Designs allows you to apply for registration of a design in many different countries or territories through a single application to the WIPO.
A list of the countries that have signed up to the Hague Agreement can be found here: http://www.wipo.int/export/sites/www/treaties/en/documents/pdf/hague.pdf
The EU, but not the UK (although the UK Government has recently announced its intention to sign up), is a party to the Hague Agreement and so designers in the EU, which of course includes UK designers, can now register designs internationally designating the EU as the contracting state. Such registrations will have the same effects as a RCD applied for via OHIM.
You can search the WIPO database by number, proprietor, international registration date, class, indication of product, priority data, designated contracting state or publication date.
OHIM recently launched Designview, a new centralised database which holds registered design information held by any of the participating national offices, OHIM and WIPO.
Currently, Bulgaria, Benelux, Estonia, Spain, Greece, Latvia, Portugal, Slovakia and OHIM are integrated into the Designview database The UK IPO and WIPO are due to integrate shortly.