Patrick originally qualified as an accountant in Norfolk. He spent the majority of his career in private practice in accounting firms in London, the last 17 years as a managing partner and tax specialist partner in one of the Big 4 firms. He then took a retirement job as Tax Policy Director at the Chartered Institute of Taxation (where he had previously been President and Member of the Council). He is also a trustee and treasurer of the think tank, the Resolution Foundation. He is a fellow of the Institute of Chartered Accountants and of the Chartered Institute of Taxation.