Methods and systems for autonomous sidelink resource allocation are provided. According to one aspect, a method performed by at least one wireless device for autonomous sidelink resource allocation comprises: at a first time, T1, transmitting a first control message announcing a first reservation of a set of radio resources for sidelink communication; at a second time, T2, transmitting a second control message announcing a second reservation of a set of radio resources for sidelink communication; and, at a third time, T3, performing a sidelink communication using the set of radio resources reserved by the second reservation. The second reservation may, for example, confirm the first reservation, cancel or partially cancel the first reservation, modify the first reservation, or completely change the first reservation.