Axial SpA (axSpA) is a chronic inflammatory condition predominantly involving the spine and sacroiliac joints (SIJ), with or without extra-spinal manifestations including peripheral arthritis, enthesitis, iritis, psoriasis and IBD. Individuals with axSpA experience significant pain, stiffness and lack of function that translates into important health care costs and increased mortality. AxSpA can be classified into two subgroups: radiographic axSpA, commonly referred to as AS, and nonradiographic axSpA (nr-axSpA). The primary difference between these two subgroups is the presence or absence of defined structural changes in the SIJ as detected on plain radiography. Although patients with nr-axSpA do not fulfil the modified New York criteria for AS [1], their burden of disease is similar [2] and they may derive as much benefit from treatment as patients with established AS. This revision of the 2005 BSR guidelines [3] provides evidence-based guidance for UK clinicians prescribing biologic drugs for adult patients across the spectrum of axSpA. This includes the criteria for starting treatment, the choice of drug and assessing response to treatment. Peripheral spondyloarthritis and juvenile SpA are outside the scope of these guidelines, and readers are referred to the BSR 2012 guidelines for the management of PsA [4].