William Diaz

Senior Manager

William Diaz

William Diaz
William Diaz
  • People

Senior Manager

William Diaz

Country / Territory

  • United KingdomUnited Kingdom

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  • English

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Email

[email protected]

T:+44 (0)207 090 9272

F:+44 (0)207 090 9101

Fragomen in London

Fragomen LLP

1st Floor, 95 Gresham St,

London EC2V 7NA

United Kingdom

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  • English

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Email

[email protected]

T:+44 (0)207 090 9272

F:+44 (0)207 090 9101

Fragomen in London

Fragomen LLP

1st Floor, 95 Gresham St,

London EC2V 7NA

United Kingdom

Connect via Linkedin

Get in touch

Languages

  • English

Contact information

Email

[email protected]

T:+44 (0)207 090 9272

F:+44 (0)207 090 9101

Fragomen in London

Fragomen LLP

1st Floor, 95 Gresham St,

London EC2V 7NA

United Kingdom

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William is a Senior Manager based in Fragomen’s London office. He assists clients in a variety of industries including finance, technology and entertainment, with a particular emphasis on assisting with complex consular filing for treaty investors, intracompany transferees and individuals of extraordinary ability.

William frequently advises small and medium-sized enterprises throughout the EMEA region in expanding to the U.S. and transferring key personnel. These clients range from start-ups to long established businesses across a range of professions. 

He has previously volunteered with various organisations, including a civil liberties non-profit and an international criminal tribunal. 

Education

  • Leiden University, LL.M., 2011
  • Pace University School of Law, J.D., 2009
  • Fordham University, B.A., 2005

More from William

Admissions

Immigration Credentials: Registered Attorney with the United States Department of Justice’s Executive Office for Immigration Review, 2013-present

Bar Admissions: New York State

Professional accomplishments

Member, American Immigration Lawyers Association (AILA)

Former Member, AILA CBP Liaison Committee

Experience

Obtained a nonimmigrant waiver of inadmissibility for a noted entertainer with previous criminal convictions.

Advised a multinational vehicle manufacturer in transferring key managerial and technical personnel for the expansion of their U.S. operations.

Helped a search engine provider with a complex business ownership structure acquire E-2 company registration and transfer key managers and executives to the United States.

Devised strategies to ensure a television production company could transfer key talent on an expedited basis during a period of prolonged global disruption in U.S. visa issuance.

Advised a start-up technology marketing firm and guided U.S. expansion strategy to support treaty investor visas for key managerial and specialist personnel.

Publications and lectures

Author, “Leading Britain’s Conversation: One Old Arrest Can Stop You Entering the USA, Even If You Were Never Convicted.” Fragomen, 16 March 2026.

Author, “Tightening immigration rules will impact the games industry in 2026.” Games Industry, 6 February 2026.

Author, “Games Industry: US H-1B Visas: Alternatives to a $100,000 Fee.” Fragomen, 29 October 2025.

Author, “Tech and Global Mobility: The impact of the new US Administration.” Computer Weekly, 4 March 2025.

Panelist, “Bobbing for Visas: Alternative Uses for the B Visa Category.” AILA Rome District Chapter Fall Conference 2023, London, UK, October 2023.

Presenter, “US Growth Programme: Visas for investment and expansion.” TechNation US Growth Workshop 3.0, London, UK, September 2022.

Panelist, “Ch-Ch-Changes: Regulatory, Policy, and Adjudications.” AILA National Conference 2020, Webinar, July 2020.

Presenter, “US Visas for Irish Investors.” Dublin Chamber of Commerce, Dublin, Ireland, February 2020.

Presenter, “Obtaining the Right Visas.” UK Department of International Trade, Cambridge, UK, October 2019.

Presenter, “Visa for US expansion.” Fingal Dublin Chamber, Dublin, Ireland, February 2019.

Presenter, “US Immigration for Investors.” South West World Trade Summit, Bristol, UK, July 2018.

Presenter, “US Immigration for Latvian Investors.” Gateway to the USA Program, Riga, Latvia, May 2018.

Panelist, “Humanitarian Options of Last Resort.” AILA National Conference 2017, New Orleans, Louisiana, June 2017.

Co-author, “Humanitarian Options of Last Resort.” AILA Immigration Practice Pointers (2017-18 Ed.), Pages 575-585, 2017.

Panelist, “Advanced E Visas.” AILA Rome District Chapter Fall Conference 2016, Amsterdam, Netherlands, October 2016.

Author, “Common US immigration consequences of mergers and acquisitions.” Human Resource Management International Digest, Volume 23, Issue 7 (2015). Print and web.

Author, “Want to work in the US? The secret to securing a successful application.” The Stage, September 25, 2015. Web.

Author, “Global Mobility Strategies for SMEs Expanding to the US.” Corporate Vision Magazine, August 2015: 42-43. Print and web.

Author, “From Posting to Permanent Residency.” Global: The International Briefing, December 2015: 40-41. Print and web.

Author, “Transferring Professional Athletes to the U.S.” HRreview, July 10, 2015. Web.

Author, “US visa eligibility: five HR issues when transferring employees.” Personnel Today, August 28, 2015. Web.

Panelist, "Legal IT Roundtable." Roundtable event, The Law Society Gazette, London, UK, July 2015.

Presenter, “US immigration for start-ups.” Presentation, Access to the US and the US Ignite Program, London, UK, June 2015.

Contributor, “Clarkson faced police interview over attack.” The Times, 27 March 2015.

Presenter, “US immigration overview.” Presentation, Techstars, London, UK, January 2015.

Author, “Dualist, but not Divergent: Evaluating United States Implementation of the 1267 Sanctions Regime.” Liberty University Law Review, Volume 5, Issue 3 (2011): 333-378. Print and web.

William’s insights

March 16, 2026 | Media mentions

Leading Britain's Conversation: One Old Arrest Can Stop You Entering the USA, Even If You Were Never ConvictedRead more

February 9, 2026 | Media mentions

Games Industry: Tightening Immigration Rules Will Impact the Games Industry in 2026Read more

October 29, 2025 | Media mentions

Games Industry: US H-1B Visas: Alternatives to a $100,000 FeeRead more
More related insights

William’s insights

March 16, 2026 | Media mentions

Leading Britain's Conversation: One Old Arrest Can Stop You Entering the USA, Even If You Were Never ConvictedRead more

February 9, 2026 | Media mentions

Games Industry: Tightening Immigration Rules Will Impact the Games Industry in 2026Read more

October 29, 2025 | Media mentions

Games Industry: US H-1B Visas: Alternatives to a $100,000 FeeRead more
More related insights

William’s insights

March 16, 2026 | Media mentions

Leading Britain's Conversation: One Old Arrest Can Stop You Entering the USA, Even If You Were Never ConvictedRead more

February 9, 2026 | Media mentions

Games Industry: Tightening Immigration Rules Will Impact the Games Industry in 2026Read more

October 29, 2025 | Media mentions

Games Industry: US H-1B Visas: Alternatives to a $100,000 FeeRead more
More related insights

Country / Territory

  • United KingdomUnited Kingdom

Get in touch

Languages

  • English

Contact information

Email

[email protected]

T:+44 (0)207 090 9272

F:+44 (0)207 090 9101

Fragomen in London

Fragomen LLP

1st Floor, 95 Gresham St,

London EC2V 7NA

United Kingdom

Connect via Linkedin

William’s insights

March 16, 2026 | Media mentions

Leading Britain's Conversation: One Old Arrest Can Stop You Entering the USA, Even If You Were Never ConvictedRead more

February 9, 2026 | Media mentions

Games Industry: Tightening Immigration Rules Will Impact the Games Industry in 2026Read more

October 29, 2025 | Media mentions

Games Industry: US H-1B Visas: Alternatives to a $100,000 FeeRead more
More related insights

Share

  • Twitter
  • Facebook
  • LinkedIn

Share

  • Twitter
  • Facebook
  • LinkedIn

Get in touch

Languages

  • English

Contact information

Email

[email protected]

T:+44 (0)207 090 9272

F:+44 (0)207 090 9101

Fragomen in London

Fragomen LLP

1st Floor, 95 Gresham St,

London EC2V 7NA

United Kingdom

Connect via Linkedin

William’s insights

March 16, 2026 | Media mentions

Leading Britain's Conversation: One Old Arrest Can Stop You Entering the USA, Even If You Were Never ConvictedRead more

February 9, 2026 | Media mentions

Games Industry: Tightening Immigration Rules Will Impact the Games Industry in 2026Read more

October 29, 2025 | Media mentions

Games Industry: US H-1B Visas: Alternatives to a $100,000 FeeRead more
More related insights

Share

  • Twitter
  • Facebook
  • LinkedIn

Share

  • Twitter
  • Facebook
  • LinkedIn

Get in touch

Languages

  • English

Contact information

Email

[email protected]

T:+44 (0)207 090 9272

F:+44 (0)207 090 9101

Fragomen in London

Fragomen LLP

1st Floor, 95 Gresham St,

London EC2V 7NA

United Kingdom

Connect via Linkedin

William’s insights

March 16, 2026 | Media mentions

Leading Britain's Conversation: One Old Arrest Can Stop You Entering the USA, Even If You Were Never ConvictedRead more

February 9, 2026 | Media mentions

Games Industry: Tightening Immigration Rules Will Impact the Games Industry in 2026Read more

October 29, 2025 | Media mentions

Games Industry: US H-1B Visas: Alternatives to a $100,000 FeeRead more
More related insights

Share

  • Twitter
  • Facebook
  • LinkedIn

Share

  • Twitter
  • Facebook
  • LinkedIn

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Senior Manager Manu George analyzes how recent disruptions in the UAE’s immigration landscape underscore the need for always‑on mobility readiness, outlining five core pillars that help organisations strengthen workforce visibility, manage compliance proactively and mitigate geopolitical and operational risks.

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Fragomen earned top national and regional rankings in Chambers USA 2026, including its 13th consecutive year in Band 1 nationwide.

Learn more

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Prepared, Not Reactive: What UAE HR and Mobility Teams Must Build for the Long Run

Senior Manager Manu George analyzes how recent disruptions in the UAE’s immigration landscape underscore the need for always‑on mobility readiness, outlining five core pillars that help organisations strengthen workforce visibility, manage compliance proactively and mitigate geopolitical and operational risks.

Learn more

Media mentions

Global Mobility Lawyer: An Irish Goodbye: Closure of the Immigrant Investor Pathway and Its Remaining Opportunities

Senior Manager Samantha Arnold examines the remaining opportunities under Ireland’s winding-down Immigrant Investor Programme and what they mean for eligible investors and their families.

Learn more

Blog post

Beyond the UK's Net Migration Decline: What the Data Reveals

Government Affairs Strategy Director Shuyeb Muquit analyses the UK’s latest net migration decline, exploring what the data reveals about policy impact, economic trade‑offs and the risks of over‑correction in future migration strategy.

Learn more

Media mentions

Bloomberg: Trump’s Green-Card Crackdown Sparks Outcry From Confused Lawyers

Partner Bo Cooper discusses the practical considerations facing employers and foreign nationals amid recent changes to green card processing.

Learn more

Blog post

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In this second installment of the Business Immigration After the Midterms series, Partner K. Edward Raleigh explores how post‑election enforcement risks for employers are expanding beyond federal agencies to include states, Congress, private plaintiffs and AI‑driven scrutiny, reshaping how workforce decisions are evaluated and challenged.

Learn more

Video

Full-Time | #FragomenFC - Ep.18

In this #FragomenFC episode, Partner Rick Lamanna, Senior Manager Sergio Flores and Senior Associate Jake Paul Minster discuss final travel and immigration considerations ahead of the 2026 FIFA World Cup.

Learn more

Media mentions

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Senior Manager Samantha Arnold discusses Ireland's citizenship framework and the gaps that can remain following reforms to birthright citizenship.

Learn more

Video

Sponsor Guide: Brazil Family Reunion Visa Essentials

In this video, Partner Diana Quintas discusses how Brazil’s family reunion visa supports long-term international assignments and outlines key eligibility, documentation and compliance considerations for employers and families relocating to Brazil.

Learn more

Blog post

Immigration and Employment in Chile: Legal Requirements for Foreign Workers

Attorney María José Clarke explores Chile’s intensified immigration enforcement framework under President José Antonio Kast, examining new employer compliance obligations, work authorization rules for foreign nationals and the legal and financial consequences of unauthorized employment.

Learn more

Media mentions

The PIE: New UKVI Compliance Metrics for Universities Take Effect Today

Senior Manager Jonathan Hill examines how the UK's new RAG rating system and stricter compliance metrics could shape universities' approaches to international student recruitment and sponsorship compliance.

Learn more

Blog post

EU Inc. Signals a Shift: Why Immigration Will Matter to Europe’s New Corporate Agenda 

Knowledge Management Director Ana Sofia Walsh and Senior Client Engagement Manager Soraya Driessen examine the European Commission’s EU Inc. proposal and its potential to reshape corporate structures across the EU, highlighting the resulting complexities and unresolved questions for immigration, work authorization and cross-border workforce mobility.

Learn more
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