A fractional head of tax holds the senior tax role part-time and on an ongoing basis. An interim head of tax fills the role full-time for a fixed period. Outsourced compliance hands the preparation and filing of returns to a firm. A full-time head of tax is an employee. They solve different problems, so the right choice depends on what is missing: senior ownership, cover for a gap, filing capacity, or all three every day.
When a family office or founder-led group asks the question, check for the first gap before the others. The returns may be filed on time while nobody senior owns the position behind them.
What does each model actually give you?
| Model | Who holds the role | Time | Best at |
|---|---|---|---|
| Full-time head of tax | An employee | Every working day | Large groups where tax is a daily operational function |
| Interim head of tax | A contractor, usually full-time | A fixed period | Covering a vacancy, a transaction or a restructuring |
| Fractional head of tax | A senior adviser or team on retainer | Part-time, ongoing | Senior ownership where the work doesn’t fill a week |
| Outsourced compliance | An accounting or tax firm | Per filing or per year | Preparing and filing returns |
Brewer Morris, a recruiter of senior tax people, draws the same line between interim and fractional: interim covers a gap, and fractional is a standing arrangement for organisations that need senior oversight but not a full-time role (Brewer Morris, 2025).
When does an interim head of tax fit?
When the role exists and is empty. A head of tax has left, a replacement will take months to find, and returns, audits or a deal can’t wait. An interim hire keeps the function running and hands over to the permanent person.
Interim is a poor fit where there has never been a head of tax. The interim person arrives, builds the files and the calendar, and leaves when the contract ends. Unless someone is ready to take over, the family or group is back where it started.
When does outsourced compliance fit?
When the gap is filing capacity. A firm prepares the corporate tax and VAT returns, keeps the deadlines and answers routine questions on those returns.
It doesn’t usually cover the decision before the return: whether a new company should sit in a free zone, whether a payment to a director is at market value, whether a foundation still meets the conditions for transparency. The firm answers the question it is given, but someone else has to decide which questions to ask, and check that the advice from each firm fits together.
Representation before the Federal Tax Authority (FTA) also has rules of its own. A tax agent is a person registered with the FTA who is appointed to represent another person before it; nobody may practise as a tax agent in the UAE without being listed on the FTA’s register and licensed locally (Articles 1 and 12 of Federal Decree-Law No. 28 of 2022 on Tax Procedures, FTA). Whichever model you choose, ask who will act as your tax agent where one is needed.
When does a fractional head of tax fit?
When the work needs senior judgement every month but not every day. Signs include advisers in three or more countries, a relocation, a sale, new UAE companies or a foundation, and related-party charges nobody has priced. Our article on when a family office needs a head of tax lists eight.
A fractional head of tax owns the position and keeps it. They hold the entity register and the positions log, review returns before they are filed, coordinate the accountants and lawyers, and sit close enough to the family or the CFO to see decisions before they are signed. The accountants keep preparing the returns, and that is why the two often run together: the accountants prepare, and the fractional head of tax owns and reviews.
When does a full-time hire fit?
When tax fills a senior person’s week. A group should hire if it has many entities filing in many countries, a regular flow of transactions or a tax team that needs managing every day. A fractional head of tax can still help there, by reviewing the positions behind the returns or adding depth in a country or tax the employee doesn’t cover. Our cost comparison sets out what a full-time hire costs in the UAE, using published recruiter data.
How do the models compare on cost, coverage and accountability?
Cost follows the shape of each model. A full-time hire carries salary and employment costs whether or not the work arrives. Interim is paid for the period of the contract, and outsourced compliance is priced per filing or per year. A fractional arrangement is a fixed fee for an agreed scope and level of access.
Coverage is where they differ most: one employee, or one interim contractor, brings one person’s experience. A fractional arrangement run by a team can bring in a specialist for transfer pricing or a foreign country without a new search each time.
Accountability is the question to settle first. Write down who owns the overall position, who prepares each return, who reviews it and who deals with the FTA. A model that leaves any of those blank is the wrong model, whatever it costs.
Can you combine them?
Yes. Combinations that work include:
- outsourced compliance for the returns, with a fractional head of tax owning and reviewing the positions;
- an interim head of tax for a vacancy, with a fractional arrangement afterwards if the volume of work doesn’t justify a permanent hire;
- a full-time tax manager, with a fractional head of tax above them for the decisions the manager shouldn’t take alone.
How Within fits
Within, by PBF, is fractional tax advisory: your tax team, within your business. It is a senior team rather than one person, working as part of your family office or business alongside your accountants, lawyers and trustees, and covering ongoing tax advice and compliance as well as questions on investments, acquisitions and listings. Your existing advisers keep their roles, and we agree with them at the outset who is responsible for tax advice, local filings and any specialist work. Your mandate sets out the work included, and we talk through any larger specialist project with you before it starts. See how Within works.
Start by writing down who owns each of the four jobs today: the overall position, preparation, review and the FTA.
Frequently asked questions
What is the difference between a fractional and an interim head of tax?
An interim head of tax is usually full-time for a fixed period, often to cover a vacancy or a transaction. A fractional head of tax is part-time and ongoing, for organisations that need senior tax ownership without a full-time role.
Is outsourced tax compliance the same as a fractional head of tax?
No. Outsourced compliance means a firm prepares and files returns. A fractional head of tax owns the overall position, reviews the returns and the positions behind them, and coordinates whoever prepares them.
Can a fractional head of tax work alongside our accountants?
Yes. The accountants prepare accounts and returns, and the fractional head of tax reviews them, sets priorities and makes sure the advice from each firm fits together.
Who can represent us before the UAE Federal Tax Authority?
A registered tax agent can be appointed to represent you before the FTA. The Tax Procedures Law requires anyone practising as a tax agent to be listed on the FTA’s register and licensed by the competent local authority.
When should we move from fractional to full-time?
When the senior tax work fills most of a week, every week. A fractional head of tax can help define the role, recruit for it and hand over the files.