Claims that decentralization could improve government accountability and responsiveness led to its adoption as a policy objective across the globe. But recent empirical work finds little evidence of “tier effects” in practice; instead, significant variation exists even between most-similar bodies. Recognizing the value of Freedom of Information (FOI) in facilitating large-scale data collection, and that the UK’s institutional diversity offers an important source of between– and within-tier variation, I compile a large new data set by emailing two separate FOI requests to 812 UK public bodies with an executive function. Identifying significant variation in timeliness and quality between UK territories, I argue that differing foundational motives can help explain patterns of responsiveness between institutions established by transparency-facing reforms and those designed to resolve conflict. A lack of evidence that lower-tier governments are generally more responsive reaffirms the recent challenges to the more fundamental claims about decentralization that informed academic debate and real-world practice.