A top OECD tax official said the group “badly needs input” as it works to rewrite global tax rules that determine where and how much tax multinationals pay.

The Organization for Economic Cooperation and Development is asking for feedback on the four proposals it’s considering as part of the project. The questions those proposals raise are “quite fundamental,” Pascal Saint-Amans, director of the OECD’s Center for Tax Policy and Administration, said at the start of a March 13-14 consultation with...