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

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

Blog post

UK Budget 2026: What the Government’s Immigration Plans Mean for Employers

In a new blog, UK Government Affairs Strategy Director Shuyeb Muquit examines what this direction could mean for employers, including why access to international talent may increasingly be considered alongside investment, productivity, innovation, regional growth and long-term workforce development.

Learn more

Video

UAE – Demographic Diversity Requirements | #MobilityMinute

The UAE’s demographic diversity requirements are designed to encourage a more diverse workforce among companies operating in the mainland jurisdiction. In this Mobility Minute, Manager Devika Thamattat explains the requirements, potential consequences of noncompliance and steps employers can take to help maintain the required nationality balance.

Learn more

Media mentions

Global Mobility Lawyer: Proposed H-1B Changes Could Increase Hiring Costs for Visa-Dependent Employers

Partner K. Edward Raleigh explains how proposed changes to the H-1B salary exemption threshold could affect US employers’ hiring practices and why enactment this year remains unlikely.

Learn more

Video

Family Reunification in Germany: Who Qualifies and How Does It Work?

In this video, Fragomen Senior Manager Katharina Vorländer explains who may qualify for family reunification in Germany, the requirements that may apply, employment and education rights for accompanying family members and important considerations when preparing an application.

Learn more

Media mentions

Dziennik Gazeta Prawna: Nielegalne zatrudnienie cudzoziemca? Pracodawca może stracić więcej niż pieniądze

Partner Karolina Schiffter discusses how digitalization is transforming immigration procedures in Poland and how law firms can adapt to evolving client expectations.

Learn more

Blog post

Who Qualifies for Costa Rica Permanent Residence?

Immigration Supervisor Michael Salas Guzman explains who may qualify for permanent residence in Costa Rica, the key benefits of permanent status and important considerations for foreign nationals planning to live and work in the country long term.

Learn more

Media mentions

BioSpace: As H-1B Visa Changes Keep Coming, Biopharmas Adjust Hiring Approach

Partner Audrea Golding discusses how H-1B visa changes, including the $100,000 fee and weighted selection process, are affecting biopharma hiring and access to global talent.

Learn more
Generic Insights

Blog post

EU Visa Code Reform: Priorities for Better Schengen Business Travel

Senior Counsel Jo Antoons and Immigration Supervisor Elisabeth Kamm outline Fragomen Consulting Europe’s recommendations for EU Visa Code reform, including more consistent business travel rules, improved visa appointment access, greater transparency and a potential Schengen-wide trusted-employer framework.

Learn more

Blog post

Argentina Announces New Citizenship by Investment Programme: What Investors Need to Know

In a new blog, Manager Sophie Jo Wasson and Country Manager María Inés Menvielle explore what is known so far, the potential mobility benefits of Argentine citizenship and what prospective applicants should consider as implementation develops.

Learn more

Media mentions

Conexão Ásia: Além da China, profissionais das Filipinas, Índia, Japão e Bangladesh se destacam na imigração laboral asiática para o Brasil

Managing Director Diogo Kloper examines how immigration trends reveal the diverse economic ties between Brazil and Asia and the role of international mobility in supporting business growth.

Learn more

Media mentions

AILA Law Journal: Administrative Proxies in Immigration Adjudication

Partner David Grunblatt examines how USCIS uses administrative proxies in immigration adjudication and explains why these tools must support, rather than replace, statutory standards and individualized legal analysis.

Learn more

Blog post

International Talent in the Netherlands: Building a Talent Pipeline Without Losing Sight of Compliance

Manager Cherida Hooijer and Immigration Assistant Manager Kaatje Droesbeke examine how employers in the Netherlands can build an international student-to-graduate talent pipeline while managing the immigration and employment compliance requirements that apply at each stage.

Learn more

Blog post

UK Budget 2026: What the Government’s Immigration Plans Mean for Employers

In a new blog, UK Government Affairs Strategy Director Shuyeb Muquit examines what this direction could mean for employers, including why access to international talent may increasingly be considered alongside investment, productivity, innovation, regional growth and long-term workforce development.

Learn more

Video

UAE – Demographic Diversity Requirements | #MobilityMinute

The UAE’s demographic diversity requirements are designed to encourage a more diverse workforce among companies operating in the mainland jurisdiction. In this Mobility Minute, Manager Devika Thamattat explains the requirements, potential consequences of noncompliance and steps employers can take to help maintain the required nationality balance.

Learn more

Media mentions

Global Mobility Lawyer: Proposed H-1B Changes Could Increase Hiring Costs for Visa-Dependent Employers

Partner K. Edward Raleigh explains how proposed changes to the H-1B salary exemption threshold could affect US employers’ hiring practices and why enactment this year remains unlikely.

Learn more

Video

Family Reunification in Germany: Who Qualifies and How Does It Work?

In this video, Fragomen Senior Manager Katharina Vorländer explains who may qualify for family reunification in Germany, the requirements that may apply, employment and education rights for accompanying family members and important considerations when preparing an application.

Learn more

Media mentions

Dziennik Gazeta Prawna: Nielegalne zatrudnienie cudzoziemca? Pracodawca może stracić więcej niż pieniądze

Partner Karolina Schiffter discusses how digitalization is transforming immigration procedures in Poland and how law firms can adapt to evolving client expectations.

Learn more

Blog post

Who Qualifies for Costa Rica Permanent Residence?

Immigration Supervisor Michael Salas Guzman explains who may qualify for permanent residence in Costa Rica, the key benefits of permanent status and important considerations for foreign nationals planning to live and work in the country long term.

Learn more

Media mentions

BioSpace: As H-1B Visa Changes Keep Coming, Biopharmas Adjust Hiring Approach

Partner Audrea Golding discusses how H-1B visa changes, including the $100,000 fee and weighted selection process, are affecting biopharma hiring and access to global talent.

Learn more
Generic Insights

Blog post

EU Visa Code Reform: Priorities for Better Schengen Business Travel

Senior Counsel Jo Antoons and Immigration Supervisor Elisabeth Kamm outline Fragomen Consulting Europe’s recommendations for EU Visa Code reform, including more consistent business travel rules, improved visa appointment access, greater transparency and a potential Schengen-wide trusted-employer framework.

Learn more

Blog post

Argentina Announces New Citizenship by Investment Programme: What Investors Need to Know

In a new blog, Manager Sophie Jo Wasson and Country Manager María Inés Menvielle explore what is known so far, the potential mobility benefits of Argentine citizenship and what prospective applicants should consider as implementation develops.

Learn more

Media mentions

Conexão Ásia: Além da China, profissionais das Filipinas, Índia, Japão e Bangladesh se destacam na imigração laboral asiática para o Brasil

Managing Director Diogo Kloper examines how immigration trends reveal the diverse economic ties between Brazil and Asia and the role of international mobility in supporting business growth.

Learn more

Media mentions

AILA Law Journal: Administrative Proxies in Immigration Adjudication

Partner David Grunblatt examines how USCIS uses administrative proxies in immigration adjudication and explains why these tools must support, rather than replace, statutory standards and individualized legal analysis.

Learn more

Blog post

International Talent in the Netherlands: Building a Talent Pipeline Without Losing Sight of Compliance

Manager Cherida Hooijer and Immigration Assistant Manager Kaatje Droesbeke examine how employers in the Netherlands can build an international student-to-graduate talent pipeline while managing the immigration and employment compliance requirements that apply at each stage.

Learn more
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Important Updates
Important Updates
October 30, 2026 | Republic of the PhilippinesPhilippines: Amendments to Simplify and Streamline Labor Market Test, Other Alien Employment Permit Processes
October 30, 2026 | ChinaChina: APEC Business Travel Card Validity Extended
October 30, 2026 | IrelandIreland: Employment Permits Portal Offline Following Unauthorized Activity
October 30, 2026 | IrelandIreland: Short Stay Visa Waiver Programme Extended
October 30, 2026 | 🌐Minimum Salary Changes Announced
October 30, 2026 | Republic of the PhilippinesPhilippines: Amendments to Simplify and Streamline Labor Market Test, Other Alien Employment Permit Processes
October 30, 2026 | ChinaChina: APEC Business Travel Card Validity Extended
October 30, 2026 | IrelandIreland: Employment Permits Portal Offline Following Unauthorized Activity
October 30, 2026 | IrelandIreland: Short Stay Visa Waiver Programme Extended
October 30, 2026 | 🌐Minimum Salary Changes Announced
October 30, 2026 | Republic of the PhilippinesPhilippines: Amendments to Simplify and Streamline Labor Market Test, Other Alien Employment Permit Processes
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