Arcos Tax Advisory Services | The Stanley Building, 7 Pancras Square, London N1C 4AG, United Kingdom

About Us

Arcos Tax Advisory Services was founded in March 2021 by Ishali Patel who saw a gap in the market for affordable, good quality US and UK tax advice. Arcos is founded on three core values, fairness, empathy and trust (find out more about our values) and these are the values that the company aspires to live and breathe in all dealings with our clients.

After spending her career in mid-tier to large accounting firms looking after the US and UK tax needs of Ultra-High and High Net Worth clients, Ishali decided to set up Arcos Tax with the aim to make the high level and complex advice that she has given throughout her career, more accessible to the people who need it and at a fair price. 

In August 2023, Arcos Tax Advisory Services merged operations with Trowbridge Professional Corporation, an international tax practice, headquartered in Toronto, Canada.

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Ishali is a dually qualified US and UK tax adviser being both an IRS Enrolled Agent in the US, authorised to represent her clients in front of the IRS and a Chartered Tax Adviser (CTA) in the UK. She spent over 16 years working in the UK and Hong Kong, where her focus was on helping globally mobile people and families with their US and UK tax affairs. She is also a part-time tutor, teaching the US tax paper for the Chartered Institute of Taxations’ Advanced Diploma in International Taxation (ADIT) qualification and thoroughly enjoys helping students navigate the complex world of US tax.

In her spare time, Ishali enjoys being a loving pawrent to her cocker spaniel, Oscar (hint as to where the company name came from!), reading and brushing up on her Korean language skills.

What Our Clients Say


I can’t recommend Ishali Patel strongly enough. Due to a change in personal circumstances I had a tight deadline to complete my US tax obligations. Ishali was not only very knowledgeable on both UK and US tax matters but also provided invaluable support, advice and guidance. She was able to ...

Hans-Erik A

Ishali is terrific. Her expert guidance has been instrumental in navigating the maze of US expat tax regulations. She is extremely responsive, clear, and attentive to the needs and concerns of the customer – truly wonderful to work with. I enthusiastically and unreservedly recommend Ishali and Arcos.

Gabriel R

Great service, very responsive and proactive. I have only good things to say about Arcos! Ishali Patel has a very complete knowledge of both US and UK Tax and did help me fantastically in my transition from US to UK.

Bradley A

Ishali is wonderful. She has offered us very good advice and is always a pleasure to work with. I recommend her in the highest terms.