The charity might also invite users of www.adviceguide.org.uk to make donations after using the service.
Adviceguide complements the charity's bureaux by offering information and fact sheets to the public on subjects such as debt, benefits, housing, employment, consumer affairs and discrimination.
According to the charity, more people sought help online than visited their local bureaux last year. Adviceguide visitors are currently being surveyed to gauge opinion on offering advertising.
Rachel Groves, head of fundraising at Citizens Advice, said: "Charities are increasingly working with corporations as a way of fundraising. We could raise funds and improve the service even further."
Citizens Advice has not yet estimated how much money the site could raise from both of the proposed income streams.