Flowers laid at The Monument following the 29 November London Bridge attack will be composted, and the resulting compost made available to the families of the victims.
Non-floral tributes, including messages, cards, and candles, will be stored at the City of London Corporation’s London Metropolitan Archives.
The tributes will be carefully moved this Sunday 12 January, after prayers held at The Monument.
The ceremony at 12.30pm is open to people of all faiths and none.
The service will be immediately followed by the annual blessing of the river at 12.45pm.
Prayers will be offered for all those who use London Bridge or the waters of the Thames.