Methods, systems, and devices for wireless communication are described to support phase continuity in uplink transmissions within a bundle interval. In a first example, a user equipment (UE) may determine bundle intervals for an uplink channel transmission based on a transmission time interval (TTI) format pattern and a bundle size. Bundle intervals may start on a next available uplink TTI after an end of a preceding bundle interval, such that each bundle interval may include at least one uplink TTI. In a second example, the UE may use frequency resources for repetitions of the uplink channel transmission within a bundle interval based on an index of the bundle interval. In a third example, the UE may not bundle some repetitions of the uplink channel transmission in a same bundle interval, and may use different frequency resources for the repetitions, based on one or more phase continuity rules.