Neoco, whose clients include Microsoft, GlaxoSmithKline and Samsung, was elected to the IPA on the same day as four more agencies -- Beaconbrands, Brave, Offshore International Advertising and Seven Stones.
This takes the total number of agencies to join the IPA this year to 16, compared to 11 in 2008 and brings the overall number of member agencies in the IPA to 270.
UK advertising, media and marketing communications agencies that are elected as members of the IPA have access to a range of services, awards and networking opportunities and allows organisations to promote their talents in the wider industry.
Hamish Pringle, director general of the IPA, said it was "good to see that so many agencies continue to recognise these valuable membership benefits, despite the recession".
The IPA's members handle more than 80% of the UK's advertising agency business which has an estimated value of £17.7bn.