The Adjudicator's Office deals with complaints about HM Revenue & Customs, the Valuation Office Agency and the Insolvency Service. The site includes annual reports and information and guidance on the complaint procedure.

The Chartered Institute of Taxation (CIOT), which was founded in 1930 and granted its Royal Charter in 1994, is a UK based professional body concerned with all aspects of taxation. The “Policy and Technical” section of the web site  includes technical articles from CIOT's monthly journal Tax Adviser January 2000 onwards. "Professional Standards" includes CIOT's byelaws and regulations as well as a number of guidance documents intended for members but freely available on the site. Annual reports 1997 onwards are in the "About Us" section. There is also an archive of press releases January 2001 onwards in "Media Centre."

The Central Fraud Division was formed in April 2010 by the merger of the Fraud Prosecution Division and Revenue and Customs Division of the CPS, the latter of which was itself the product of a merger between the CPS and the formerly independent Revenue and Customs Prosecutions Office (RCPO). The web site explains how and in what areas the CFG operates, and the Publications section reproduces legal guidance and the annual reports of the former RCPO, 2005-2008.

The web site of the European Commission's Taxation and Customs Union Directorate-General includes links to European Union customs and taxation legislation on the Eur-Lex database; links to cases from the European Court of Justice on tax and customs matters; several customs and taxation databases developed and operated by the Commission; proposals and consultations; and a “What's New” section for current developments.

Gray's Inn Tax Chambers is a set of barristers' chambers specialising in revenue law. The site includes over 20 articles written by members of chambers, and digests of over 50 court and tribunal cases in which members have been involved, most of them with links to full transcripts.

HM Revenue & Customs (HMRC) is a non-ministerial department whose main responsibility is the collection of taxes. It was created by the merger on 18 April 2005 of the former Inland Revenue and HM Customs & Excise. This section of the GOV.UK web site provides access to information on HMRC's activities, policies, publications and announcements, and to information more widely across the whole government. Select "HMRC advice and services" to access material arranged for “individuals and employees”, “employers” and “businesses and corporations”. Each of these three sections includes relevant forms, guidance, manuals, links to legislation and other documentation.

The Treasury is responsible for the government's financial and economic policy. Its web site includes budget and pre-budget documents (the Chancellor's budget speeches, budget and pre-budget reports, and press notices) and details of consultations and legislation. A link is provided to the Treasury section of the GOV.UK web site to which some site content has been moved. Archived material relating to the budgets of the previous government may be accessed via a link to the National Archives web site.

The ITPA web site holds a collection of offshore tax laws, articles, case law and other information. Some information is for members only but there is a "Library" section which is available to non-members. This includes a Portfolio of Laws link which lists legislation by jurisdiction. (Full text is only available to members: title information is given to non-members.) There are also links to full text articles from the ITPA yearbook, 2000 - 2011.

This site provides news items and a blog for those interested in tax law and trusts. It is maintained by Leigh Sagar, a practising barrister of New Square Chambers, Lincoln's Inn.

The Lowtax Network provides news and information about the tax and legal regimes in a wide variety of jurisdictions. It provides information on over 50 offshore and onshore “low tax” countries. Included is information about each jurisdiction's tax status, tax system, special offshore regimes and company forms.

Pump Court Tax Chambers is a set of barristers' chambers specialising in tax law. The site's Resources section includes a "Judgments" file of full text cases June 2005 onwards, and a small group of articles June 2010 onwards.

The main function of the Tax and Chancery Chamber of the Upper Tribunal is to decide applications for permission to appeal and appeals on points of law from decisions of the First-tier Tribunal in tax and charity cases. It was established on 1 April 2009 as a superior court of record with UK-wide jurisdiction, and on 6 April 2010 took over additionally the functions of the former Financial Services and Markets Tribunal (FSMT) and Pensions Regulator Tribunal (PRT). This section of the Justice portal site includes forms and guidance, links to procedural rules, registers of forthcoming hearings, and links to decisions on the Tribunals Judiciary web site.

The First-tier Tribunal (Tax) hears appeals against decisions relating to tax made by Her Majesty's Revenue & Customs (HMRC). It was created on 1 April 2009, replacing four former separate tax tribunals - the General Commissioners of Income Tax, the VAT and Duties Tribunal, the Special Commissioners of Income Tax and the Section 704/706 Tribunal. This section of the Justice portal site includes forms and guidance, and links to procedural rules and other legislation. The Tribunal Procedure (First-tier Tribunal) (Tax Chamber) Rules 2009 are available in an unofficial consolidated version which incorporates amendments. There is a link to a database of decisions 2002 onwards (searchable April 2003 onwards), together with a few earlier ones, on the Tribunals Judiciary web site.

This gateway site has a regularly updated list of links to web sites of interest to tax professionals and others seeking information on UK tax matters.