Tower Bridge to to be closed to pedestrians and road traffic for three months at the end of 2016.
The closure is required to allow the bascules (the lifting parts of the bridge) to be re-decked.
The City of London Corporation says that the timber decking is at the end of its life and needs replacement.
In a report to next week's meeting of the corporation's projects sub-committee, senior engineer Mark Bailey writes: "To facilitate the bascule works, a road closure of three months is estimated as necessary, which has already been discussed with Transport for London, in terms of network coordination and diversion route planning.
"The bascules will be maintained as operable to river traffic at 24 hours' notice, in order to meet our obligations under Act of Parliament.
"The programmed date for October to December 2016 coincides with those months of the year that the bascules are typically least lifted – hence limiting disruption to both river traffic and the construction works to maintain the bridge."
The project is expected to cost £3.35 million.
During previous closures of Tower Bridge special rules have been introduced to allow motorists to use London Bridge without becoming liable to pay the congestion charge.
The Tower Bridge Exhibition is expected to remain open during the works.