Who are CST

We are the United Kingdom member firm of the CST International network.We deliver specialist tax advice and chartered accounting services to private clients, family groups and international enterprises.


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CST Tax Advisors is an international network of affiliated accounting firms providing specialist tax and accounting advice to global expats and international enterprises. Our London office has been recently established to ensure that clients are able to achieve the best possible advice in the United Kingdom.

CST is the only dedicated international tax firm operating in London as such we are able to provide unique insights to our clients in the U.K.

Our Mission Statement

CST Tax Advisors aims to provided expat individuals and international private enterprises with integrated tax and accounting advice for their home country and the country in which they operate.

Our member firms are located in major international cities and we are therefore able to directly service our global clients.

Our professional contacts mean that many cross-border business matters can easily be addressed. Our professional affiliations and professional relationships allow us to co-ordinate a solution to whatever professional tax or legal issue a client may have. This reduces many of the communication difficulties when an expatriate or business person is considering an international move.

The History of CST

CST Tax Advisors was founded in 1992, by John Marcarian in Sydney, Australia. From the early days of the Firm it was recognised that the private client tax market for Australian expatriates and international businesses was a specialist market segment. In 2020 CST Tax Advisors London was established and currently offers the full range of U.K tax compliance and professional accounting services. Today CST Tax Advisors has offices in London, Sydney, Singapore and Los Angeles. Our Sydney office opened in 1992, followed by our office in Singapore in 2004 and our Los Angeles office in 2010.

John Marcarian

As John says

As John says

The beginning of the CST way was grounded in delivering quality services to the executive, private client or family business. I always believed that the relationship with the client was the foundation stone of the Firm and our obligation to maintain that relationship meant that we were not to be just about the chargeable hour and answering questions – but rather is a sense of obligation to go the extra mile to think about things that we ourselves would want done – if we were the client.

Our Key Value Proposition is to continue to provide expat individuals and international enterprises with integrated tax accounting and structuring advice for both their home markets and the international markets in which they operate. We do this by having empathy to their facts and circumstances and focusing on executing tax and business solutions.

We strongly believe that by focussing on clients living and working abroad we can deliver on the above statement through our global brand and our united delivery platform.