ADIT December 2026: the deadlines that decide whether you sit this winter

If you are planning to sit an ADIT exam this December, the next few weeks matter more than the ones after. The Chartered Institute of Taxation has set the December 2026 session for the week of 8 December, and the deadlines that let you into it fall in early September. Here is the timeline, and the order to do things in.

When the exams are

The December 2026 ADIT exams run across three days. Principles of International Taxation, the compulsory module, is on Tuesday 8 December. The United Kingdom jurisdiction option is on Wednesday 9 December. The thematic options, which this session cover Energy Resources, EU Direct Tax, EU VAT and Transfer Pricing, are on Thursday 10 December.

The deadlines that actually gate you

Here is the part people miss. You cannot enter for an exam until you are a registered ADIT student, and student registration for this session closes first, on 2 September. So if you are not yet registered, that is the deadline that really governs you. Register first, then enter for your modules by the standard deadline of 16 September. Miss that and you can still get in until 30 September, but it costs an extra late fee.

What to do now

With the compulsory Principles paper on the Tuesday, most people build their December around it. If you are taking Principles plus a jurisdiction or thematic option, check your chosen modules sit on different days across the three-day week, which they do, and plan your revision backward from 8 December. Booking your entry early also settles the question you might otherwise keep dodging, which is exactly which modules you are committing to this winter. Once the entry is in, the decision is made and the revision plan can be real.

One practical note on timing. Because student registration closes two weeks before the exam entry deadline, leaving both to mid-September is risky. If there is any chance you will sit in December, get the registration done now so the 16 September entry deadline is the only one you have to watch.

The career this is really about

Here is the part worth holding onto while you grind through Principles. A module on transfer pricing or the UK option is not just a line on the ADIT record, it is the exact language spoken in the roles people move into next: transfer pricing associate at a Big Four firm, international tax analyst inside a multinational's in-house team, cross-border advisory at a mid-tier practice. Because ADIT is jurisdiction-neutral, a candidate in Lagos, London or Lisbon is reading for the same portable credential, which is why it keeps turning up in job specs that used to ask only for a local qualification.

We keep coming back to this because it is a running theme here, not a closing line on a deadline post. Each week Global Tax Studies pulls out the roles these exams open, the newly qualified positions worth watching, and the routes MojiTax candidates have taken after they pass, so the paper in front of you always sits next to the job it leads to. If that is the reason you are sitting in the first place, the community is where those conversations happen.

MojiTax

A note from us, since we run this blog

Sitting ADIT in December?

Global Tax Studies is run by the team at MojiTax, who build structured ADIT training across the Principles and option modules, with lessons, exam-style questions and marked mocks. If you are entering for December and want a clear revision plan from now to exam day, start here. We always say when we are pointing at our own courses, and this is one of those times.

See MojiTax ADIT training

Join the discussion

Sitting ADIT this December, or still weighing it up? Bring your questions and compare plans with other candidates. You can pick whichever room you already live in: our WhatsApp group, the LinkedIn group, the Facebook group. They all connect back through the Global Tax Studies community page.

Source: CIOT ADIT exam timetable at tax.org.uk/adit/exam-timetable. Always confirm dates and fees on the CIOT portal before you act, since sessions can change.