Dermot O’Brien

I am a VAT specialist and the commencement of my career in VAT predates the arrival of the fax machine. I spent 10 years working in VAT with the Revenue Commissioners, where I gained significant expertise in VAT law and administration but felt that there must be another side to the story.

I further developed my tax expertise in the private sector, working in a number of firms and my roles included heading the Indirect Tax practice in KPMG, before becoming a VAT partner in BDO.

Something was still gnawing at my professional bones when I realised that there was no independent VAT consulting practice in Ireland. Not stopping to consider whether there might be a good reason for this, I established Dermot O’Brien & Associates in 2004. Shortly after establishing the firm, my ex-colleague from BDO, Gabrielle Dillon, came on board and I have been listening ever since. As Gabrielle is from Mayo and I am a noble Dub, we rarely discuss Gaelic Football.

However, VAT consulting is what we were always about and I had some peculiar need to be more immersed in tax and became a Council Member of the Irish Taxation Institute, culminating in being President (2006-2007), a position I feel honoured to have held.

I have written, and co-written, a couple of books on VAT but to borrow a title from The Who, I “Won’t Get Fooled Again”. (For younger readers, The Who also predate the fax machine.)

I have also acted as an expert adviser to the IMF on tax issues, and have conducted missions in a number of rarely-visited Central European and Southern African states. I previously represented the ITI on the VAT Sub-Committee of the Taxes Administration Liaison Committee (TALC).

Gabrielle and I joined Twomey Moran in March 2020.


Rugby, cricket, wine and bad golf.


Fellow of the Irish Taxation Institute, Member of the Institute of Directors.


Article of the Year recipient, Irish Tax Review.