About the Author — Amy Choi, CPA

Amy Choi, CPA (a Certified Public Accountant licensed in Delaware), has worked in international tax practice for more than 18 years. Amy studied economics in Korea and has handled cross-border tax from both sides, Korean and U.S.

Amy spent the early part of this career at global tax firms in Seoul and Silicon Valley. The work was individual tax for employees of multinational companies who moved across borders. Amy prepared U.S. individual income tax returns for overseas assignees, rotational workers and foreign employees. The work also included tax equalization calculations, estimated tax calculations, advice on stock compensation (RSUs) and retirement accounts, risk reviews for business travelers, and overall management of client companies.

In Korea, Amy advised on tax procedures for the withholding and filing rules that apply to the income of foreign employees. Amy also took part in global FATCA and CRS projects for financial-institution clients. This work gave Amy a close view, from both countries, of how Korean tax law and U.S. tax law treat the same income of the same person at different times and on different forms.

More recently, Amy has worked on international tax for multinational companies. The work covers permanent establishment, VAT, transfer pricing, withholding and foreign tax credit issues for overseas affiliates. It also means explaining to people who are not tax specialists how changes in law and in the business affect tax. Turning difficult rules into plain language is also how this book is written.

This book starts from that experience. Its starting point is this: decide on refunds and deductions by the evidence for claiming them, not by the wish to receive them. Households that span two countries need even more evidence. So the book makes three promises to the reader.

• Every number in this book states its year and its source.
• Values that change with assumptions are shown as a range, not stated as a single number.
• Anything not confirmed is marked as not confirmed, and that space is left blank.

The same reason is why the book and the site are built to use values from the same set of rules. A household's situation entered on the site and the examples in the book can then be read on the same scale.

The author is co-founder and CFO (part-time, unpaid side venture) of AI Financial Investing LLC and has an interest in the aitaxinvesting.com site.