The review comes six months after the government savings organisation rebranded as National Savings & Investments, in a bid to update its image.
It is seeking agencies to handle its above- and below-the-line marketing and media planning and buying. The creative account was held by BMP DDB, but that contract expired 18 months ago.
OMD UK is the media incumbent, EHS Brann handles direct marketing and Citigate Lloyd Northover handles its brand identity. The latter oversaw the organisation's rebrand in February. National Savings drew criticism from the Conservative Party for the £2.1m relaunch, which condemned the amount of money spent was "frivolous".
National Savings has not advertised on TV since March 1999, but since the rebrand it has launched a press and direct marketing campaign to promote its premium bonds under the banner 'National Savings & Investments can make you a millionaire'.
Head of communications Tim Mack, who oversees marketing, said those agencies that are appointed must continue to highlight the new positioning of the brand.
"The modernisation programme is, in terms of customer services, new products and the new name, about us working to be the first port of call for savers and investors." He added that whether or not it would use TV again would depend on budget.