Liz Perks

Accounting Valuation Experts LLP

71-75 Shelton Street, Covent Garden
WC2G 9JQ, London, England


Peers and clients say:

"Liz has great eminence and gravitas"
"She has the knowledge to win the most complex cases"
"I would highly recommend her"


Liz is a forensic accountant with extensive experience of the accounting and quantum aspects of disputes before LCIA, ICC, UNCITRAL, ICSID tribunals and English courts. Liz holds a law degree and postgraduate diploma in legal practice from Sheffield University. She is a fellow of the Institute of Chartered Accountants in England and Wales and a trustee and chair of the Finance and Audit Committee of the British institute of International and Comparative Law (BIICL).

Describe your career to date.

I initially trained as a chartered accountant in a small practice specialising in the entertainment sector. I gained broad accounting experience including accounts preparation, audit, personal and corporate tax and royalty investigations with a very interesting set of clients. I loved the forensic aspect of the royalty investigations and so joined a Big Four professional services firm in 2000 to specialise in forensic accountancy. From then my focus has mainly been on expert witness work in the context of disputes, alongside a few investigations and a year-long compliance project into the sales and marketing practices of a global pharma company.

In 2013, I left the Big Four to help launch Haberman Ilett, a boutique forensic accounting practice. I had my first expert appointment in my own name in 2014 and have since been appointed in a wide variety of cases, including contractual, IP, valuation and transaction disputes. In 2020, Haberman Ilett was bought by Kroll, where I am now a managing director.

What is one of the most interesting cases at which you have testified?

One of the most interesting cases was an LCIA arbitration concerning the alleged breach of contract around the distribution and marketing of a product in the healthcare sector. It was interesting on lots of levels: the product and sector, the events that had occurred, the procedural process (see more below), the complexity of the loss quantification and as we had the classic ‘ships in the night’ situation with the opposing expert.

What impact can a more interventionalist approach from tribunals have on independent expert work?

Following on from my answer above, in this case the tribunal did take a more interventionalist approach. I believe this was due to the huge gap between the experts’ quantifications of loss. To illustrate the approach they took: the tribunal attended the meeting of experts (without counsel or parties) and they used this meeting to understand both of our views on all the issues and ask some questions to educate themselves (that they would maybe not ask in a hearing situation). Following this meeting, they asked the experts to jointly prepare a flexible model with options for each of the assumptions that drove the loss, so that they would be able to use the model to calculate loss once they had decided all the factual, legal and financial issues. Then in the hearing, the expert testimony was all concurrent (hot tubbing). The tribunal provided an agenda, and they led the questioning for over a day (with counsel on both sides only allowed to cross examine on any answers given). Because they had already spent a day with us in the meeting of experts, the tribunal were very well prepared and able to ask pertinent questions, challenge our answers and successfully lead the hot tub.

My view is that the approach the tribunal took led to a much higher quality of expert evidence and by the end of the hearing, I felt confident that the tribunal would come to a sensible answer on quantum. I have to say that I do not always leave a hearing with that confidence and sometimes I have no idea if the tribunal have really understood the issues and will be able to work through the complex accounting or valuation questions to come to a reasonable conclusion.

After my experience with this case, I believe that it is a tribunal’s duty to be more interventionist if they do not have the expert evidence that they need to be able to determine technical issues, for example, where the experts have different instructions, or will not engage with the opposing expert arguments, or are ‘ships that pass in the night’.

What advice do you give to junior experts looking to gain their first appointment as an expert witness?

Getting the first appointment can be tricky. I would advise junior experts to (i) tell partners that you know well that you want your first appointment and ask them to recommend you if something suitable comes along (ii) seek opportunities to work on as many cases of different types as possible, so your CV is credible and (iii) network – those relationships you build will lead to future work, you just have to be patient.

What about your role do you enjoy the most?

The thing I enjoy most about the role is the variety and the challenge. No two cases are ever the same, so the job never becomes routine. I do not specialise in any particular sector, so am in the privileged position of having a role where I am constantly learning, and I get to acquire deep knowledge of a wide range of industries and issues in businesses all over the world. I also get to work with very bright and inspiring individuals, both as colleagues and clients.