William Diaz

Senior Manager

William Diaz

William Diaz
William Diaz
  • People

Senior Manager

William Diaz

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

London

Fragomen LLP

1st Floor, 95 Gresham St,

London EC2V 7NA

United Kingdom

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Get in touch

Languages

  • English

Contact information

Email

[email protected]

T:+44 (0)207 090 9272

F:+44 (0)207 090 9101

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

London

Fragomen LLP

1st Floor, 95 Gresham St,

London EC2V 7NA

United Kingdom

Connect via Linkedin
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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

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

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

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

Explore more at Fragomen

Media mentions

AIP: Trump Administration Proposes New Six-Figure H-1B Fee

Partner Bo Cooper discusses the potential impact of the proposed $103,265 fee for cap-subject H-1B petitions on US employers and international talent in AIP.

Learn more
Generic Insights

Blog post

Luxury Retail’s Evolving Talent Needs: When Business-Critical Skills Don’t Fit Traditional Immigration Categories

In our latest blog, Canada Managing Partner Cosmina Morariu explores how aligning mobility with talent planning can help brands deploy critical expertise where it is needed.

Learn more

Podcast

Moving HQ to the Middle East: A Success Perspective with VEON - Beyond Borders Series | The Immigration Conversation

Partner Ali Haider and Director Shoaib Khaleeli speak with VEON Chief People Officer Jameel Asghar about leadership, future-ready talent, organisational resilience and VEON’s decision to relocate its headquarters to Dubai.

Learn more

Media mentions

Financial Times: Trump Administration Pauses Immigrant Visa Applications

Senior US Consular Manager Brian Simmons discusses the impact of the Trump administration’s worldwide pause on immigrant visa applications and the disruption caused by last-minute interview cancellations in the Financial Times.

Learn more

Blog post

Latin America’s Evolving Mobility Landscape: Opportunity and Complexity Advancing Together

Latin America and the Caribbean Managing Partner Leonor Echeverria explores how stronger compliance expectations, processing constraints and increasingly fragmented immigration policies are reshaping workforce mobility across the region—and where new pathways for specialized talent are emerging.

Learn more

Media mentions

Proposed $103,265 H-1B Fee: Fragomen Attorneys Examine the Potential Impact

Partners Bo Cooper and K. Edward Raleigh and Senior Counsel Mitchell Wexler discuss the potential impact of a proposed $103,265 fee for cap-subject H-1B petitions on employers and foreign talent.

Learn more
Generic Insights

Blog post

2026 Immigration Regulatory Changes: What Academic Medical Centers Need to Know

In this blog, Counsel Christopher Wendt examines four developments AMCs should have on their radar and why preparing for them may require coordination across immigration, GME, research administration, HR, benefits, finance and more.

Learn more

Blog post

Five Questions to Consider Before Seeking Residence or Citizenship in Europe

Senior Manager Andreia Florina Ghimis and Manager Pierangelo D’Errico outline five key questions to ask before seeking residency in Europe.

Learn more

Awards

Fragomen Receives Brandon Hall Group™ Gold HCM Excellence Award® for Leadership Development

Fragomen received a Brandon Hall Group™ Gold HCM Excellence Award® in the Best Leadership Development Program category for our Leadership Lifecycle initiative.

Learn more

Media mentions

People Management: Unpacking the New Overseas Talent ‘Concierge’ Service

Partner Charlotte Wills and Senior Manager Harry Goldstraw discuss the UK’s new overseas talent “concierge” service and what it means for high-growth businesses recruiting international talent.

Learn more

Blog post

A1-Bescheinigung oder Certificate of Coverage (CoC): Welches Dokument wird wann benötigt?

In this blog, Senior Manager Katharina Vorländer explains when A1 certificates and Certificates of Coverage (CoCs) may be required, the key differences between the two documents and what employers should consider before managing international assignments.

Learn more

Awards

Fragomen Attorneys Recognized in the 2027 Edition of The Best Lawyers in America™

Fragomen attorneys are recognized in the 2027 editions of The Best Lawyers in America™ and Best Lawyers: Ones to Watch® in America, including Partner Matthew Phillips and Senior Counsel Mitch Wexler as Lawyer of the Year recipients.

Learn more

Media mentions

AIP: Trump Administration Proposes New Six-Figure H-1B Fee

Partner Bo Cooper discusses the potential impact of the proposed $103,265 fee for cap-subject H-1B petitions on US employers and international talent in AIP.

Learn more
Generic Insights

Blog post

Luxury Retail’s Evolving Talent Needs: When Business-Critical Skills Don’t Fit Traditional Immigration Categories

In our latest blog, Canada Managing Partner Cosmina Morariu explores how aligning mobility with talent planning can help brands deploy critical expertise where it is needed.

Learn more

Podcast

Moving HQ to the Middle East: A Success Perspective with VEON - Beyond Borders Series | The Immigration Conversation

Partner Ali Haider and Director Shoaib Khaleeli speak with VEON Chief People Officer Jameel Asghar about leadership, future-ready talent, organisational resilience and VEON’s decision to relocate its headquarters to Dubai.

Learn more

Media mentions

Financial Times: Trump Administration Pauses Immigrant Visa Applications

Senior US Consular Manager Brian Simmons discusses the impact of the Trump administration’s worldwide pause on immigrant visa applications and the disruption caused by last-minute interview cancellations in the Financial Times.

Learn more

Blog post

Latin America’s Evolving Mobility Landscape: Opportunity and Complexity Advancing Together

Latin America and the Caribbean Managing Partner Leonor Echeverria explores how stronger compliance expectations, processing constraints and increasingly fragmented immigration policies are reshaping workforce mobility across the region—and where new pathways for specialized talent are emerging.

Learn more

Media mentions

Proposed $103,265 H-1B Fee: Fragomen Attorneys Examine the Potential Impact

Partners Bo Cooper and K. Edward Raleigh and Senior Counsel Mitchell Wexler discuss the potential impact of a proposed $103,265 fee for cap-subject H-1B petitions on employers and foreign talent.

Learn more
Generic Insights

Blog post

2026 Immigration Regulatory Changes: What Academic Medical Centers Need to Know

In this blog, Counsel Christopher Wendt examines four developments AMCs should have on their radar and why preparing for them may require coordination across immigration, GME, research administration, HR, benefits, finance and more.

Learn more

Blog post

Five Questions to Consider Before Seeking Residence or Citizenship in Europe

Senior Manager Andreia Florina Ghimis and Manager Pierangelo D’Errico outline five key questions to ask before seeking residency in Europe.

Learn more

Awards

Fragomen Receives Brandon Hall Group™ Gold HCM Excellence Award® for Leadership Development

Fragomen received a Brandon Hall Group™ Gold HCM Excellence Award® in the Best Leadership Development Program category for our Leadership Lifecycle initiative.

Learn more

Media mentions

People Management: Unpacking the New Overseas Talent ‘Concierge’ Service

Partner Charlotte Wills and Senior Manager Harry Goldstraw discuss the UK’s new overseas talent “concierge” service and what it means for high-growth businesses recruiting international talent.

Learn more

Blog post

A1-Bescheinigung oder Certificate of Coverage (CoC): Welches Dokument wird wann benötigt?

In this blog, Senior Manager Katharina Vorländer explains when A1 certificates and Certificates of Coverage (CoCs) may be required, the key differences between the two documents and what employers should consider before managing international assignments.

Learn more

Awards

Fragomen Attorneys Recognized in the 2027 Edition of The Best Lawyers in America™

Fragomen attorneys are recognized in the 2027 editions of The Best Lawyers in America™ and Best Lawyers: Ones to Watch® in America, including Partner Matthew Phillips and Senior Counsel Mitch Wexler as Lawyer of the Year recipients.

Learn more
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Important Updates
Important Updates
August 27, 2026 | 🌐Middle East - The Latest News on Mobility and Travel Considerations
August 28, 2026 | MalaysiaMalaysia: New Photograph Verification Processes
August 28, 2026 | United StatesUnited States: DHS Proposal to Eliminate 60-Day Nonimmigrant Grace Period Clears Federal Review
August 28, 2026 | 🌐Worldwide: Temporary Ebola-Related Entry Restrictions Introduced
August 27, 2026 | United StatesAIP: Trump Administration Proposes New Six-Figure H-1B Fee
August 27, 2026 | 🌐Middle East - The Latest News on Mobility and Travel Considerations
August 28, 2026 | MalaysiaMalaysia: New Photograph Verification Processes
August 28, 2026 | United StatesUnited States: DHS Proposal to Eliminate 60-Day Nonimmigrant Grace Period Clears Federal Review
August 28, 2026 | 🌐Worldwide: Temporary Ebola-Related Entry Restrictions Introduced
August 27, 2026 | United StatesAIP: Trump Administration Proposes New Six-Figure H-1B Fee
August 27, 2026 | 🌐Middle East - The Latest News on Mobility and Travel Considerations
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