There has been much speculation about marriage practices in 18 th century England, and many commentators have assumed that cohabitation was common, particularly among the lower orders. More recent work on southern parishes has, however, suggested that formal marriage was the norm, and cohabitation vanishingly rare, both before and after the passage of the Clandestine Marriages Act of 1753. This article sets out to test whether that conclusion holds good for those more remote parts of the north-west in which, it has been claimed, informal practices still flourished. Drawing on a cohort of over a thousand couples identified from the Westmorland 'census' of 1787, this article discusses the challenges in tracing where and when those couples had married, and shows how all the evidence nonetheless suggests very high levels of compliance with the formal legal requirements. This in turn has important implications for the assumed completeness of parochial registers and the likelihood of family historians being able to trace a marriage.