A method performed by a wireless device (130) is described herein. The wireless device (130) operates in a wireless communications network (100). The wireless device (130) provides (602) a message to be sent to a network node (110) operating in the wireless communications network (100). The message is a first scheduled message to be sent to the network node (110) in a random access procedure. The message comprises a first indicator (707) of a type of the message. The type of message has: a) a fixed size SDU (702), and b) a one byte header (704) comprising the first indicator (707) and lacking a second indicator (713) of a length of a payload. The wireless device (130) also initiates sending (603) the provided message to the network node (110). Also described is a method performed by the network node (110) receiving (1307) and initiating processing (1302) the message, based on the first indicator (707).