In the light of broad trends to hold lobbyists accountable by voluntary or mandatory means this practice piece reviews the United Kingdom experience of lobbying self-regulation. It suggests that there are key problems with the hitherto default self-regulatory model, and that the status quo is likely to change. Over the last few years, and spanning different political administrations, a steady drip feed of controversy and scandal involving lobbying has harmed the reputation of the political system, already undermined in other ways. This damaging publicity was one of the spurs for the recent inquiry on lobbying at Westminster, and this also had an impact on manifesto commitments on lobbying in the run up to the 2010 UK general election. Lobbying reform featured in the subsequent coalition agreement. Although pressure for some form of independent oversight of lobbying has been gaining pace in the last few years, and demands for reform have intensified in the wake of recent scandals, the precise shape of lobbying regulation at Westminster is still unclear. Debate on how to regulate and make transparent relations between government, elected representatives, officials and outside interests repeatedly throws up a number of issues that will need to be addressed in whatever regime is developed. These include: agreeing a workable definition of lobbying activity, which captures both direct and indirect lobbying; setting thresholds for registration; agreeing standards and protocols for reporting lobbying activity, including information on the resources devoted to lobbying, and where these are targeted. Whatever system is developed will have to strike a balance between securing transparency (via reporting, disclosure and possibly regulation) and ensuring that barriers to participation are not created (especially for resource poor groups and ordinary citizens). It is likely that many of those engaged in lobbying that does not involve direct advocacy will seek to be excluded from full disclosure obligations. How these issues are handled will condition the scrutiny and accountability of lobbying in the United Kingdom, and ultimately play a key role in determining whether such transparency measures can contribute to rebuilding trust and confidence in the political system.