Important Updates
Important Updates
October 17, 2025 | United StatesUnited States: Second Court Challenge to New H-1B Restrictions and $100,000 Fee is Filed
October 17, 2025 | European UnionEuropean Union/Schengen Area: Internal Schengen Border Checks Situation
October 17, 2025 | NigeriaNigeria: New Mandatory Insurance for Foreign Employees
October 17, 2025 | NigeriaNigeria: New Online Temporary Work Permit Submission Process
October 17, 2025 | ThailandThailand: Mandatory Online Work Permit and Foreign Worker Registration System Forthcoming
October 17, 2025 | United StatesUnited States: Second Court Challenge to New H-1B Restrictions and $100,000 Fee is Filed
October 17, 2025 | European UnionEuropean Union/Schengen Area: Internal Schengen Border Checks Situation
October 17, 2025 | NigeriaNigeria: New Mandatory Insurance for Foreign Employees
October 17, 2025 | NigeriaNigeria: New Online Temporary Work Permit Submission Process
October 17, 2025 | ThailandThailand: Mandatory Online Work Permit and Foreign Worker Registration System Forthcoming
October 17, 2025 | United StatesUnited States: Second Court Challenge to New H-1B Restrictions and $100,000 Fee is Filed
Subscribe
Fragomen.com home
Select Language
  • English
  • French
  • French - Canadian
  • German

Select Language

  • English
  • French
  • French - Canadian
  • German
ContactCareersMediaClient Portal
Search Fragomen.com
  • Our Services
    For EmployersFor IndividualsBy IndustryCase Studies
  • Our Tech & Innovation
  • Our People
  • Our Insights
    Worldwide Immigration Trends ReportsMagellan SeriesImmigration AlertsEventsMedia MentionsFragomen NewsBlogsPodcasts & Videos
  • Spotlights
    Navigating Immigration Under the Second Trump AdministrationTravel & Mobility Considerations: Situation in the Middle EastImmigration Matters: Your U.S. Compliance RoadmapCenter for Strategy and Applied InsightsVietnamese ImmigrationView More
  • About Us
    About FragomenOfficesResponsible Business PracticesFirm GovernanceRecognition

Our Services

  • For Employers
  • For Individuals
  • By Industry
  • Case Studies

Our Tech & Innovation

  • Our Approach

Our People

  • Overview / Directory

Our Insights

  • Worldwide Immigration Trends Reports
  • Magellan Series
  • Immigration Alerts
  • Events
  • Media Mentions
  • Fragomen News
  • Blogs
  • Podcasts & Videos

Spotlights

  • Navigating Immigration Under the Second Trump Administration
  • Travel & Mobility Considerations: Situation in the Middle East
  • Immigration Matters: Your U.S. Compliance Roadmap
  • Center for Strategy and Applied Insights
  • Vietnamese Immigration
  • View More

About Us

  • About Fragomen
  • Offices
  • Responsible Business Practices
  • Firm Governance
  • Recognition
Select Language
  • English
  • French
  • French - Canadian
  • German

Select Language

  • English
  • French
  • French - Canadian
  • German
ContactCareersMediaClient Portal
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

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

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
  • PrintPrint
  • SaveSave

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, “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

October 7, 2025 | Webinar

Fragomen and Interstride Webinar Series: Immigration Options for Business Students, Investors & EntrepreneursRead more

March 5, 2025 | Media mentions

Computer Weekly: Tech and Global Mobility: The Impact of the New US AdministrationRead more

William’s insights

October 7, 2025 | Webinar

Fragomen and Interstride Webinar Series: Immigration Options for Business Students, Investors & EntrepreneursRead more

March 5, 2025 | Media mentions

Computer Weekly: Tech and Global Mobility: The Impact of the New US AdministrationRead more

William’s insights

October 7, 2025 | Webinar

Fragomen and Interstride Webinar Series: Immigration Options for Business Students, Investors & EntrepreneursRead more

March 5, 2025 | Media mentions

Computer Weekly: Tech and Global Mobility: The Impact of the New US AdministrationRead more

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

October 7, 2025 | Webinar

Fragomen and Interstride Webinar Series: Immigration Options for Business Students, Investors & EntrepreneursRead more

March 5, 2025 | Media mentions

Computer Weekly: Tech and Global Mobility: The Impact of the New US AdministrationRead more

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

October 7, 2025 | Webinar

Fragomen and Interstride Webinar Series: Immigration Options for Business Students, Investors & EntrepreneursRead more

March 5, 2025 | Media mentions

Computer Weekly: Tech and Global Mobility: The Impact of the New US AdministrationRead more

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

October 7, 2025 | Webinar

Fragomen and Interstride Webinar Series: Immigration Options for Business Students, Investors & EntrepreneursRead more

March 5, 2025 | Media mentions

Computer Weekly: Tech and Global Mobility: The Impact of the New US AdministrationRead more

Share

  • Twitter
  • Facebook
  • LinkedIn

Share

  • Twitter
  • Facebook
  • LinkedIn

Explore more at Fragomen

Video

Oman Introduces a Golden Visa Program | #MobilityMinute

Manager David Makau discusses Oman's recent introduction of a Golden Visa program.

Learn more

Media mentions

The Stage: Actors, Dancers and Writers Set to Escape Visa Ban

Partner Louise Haycock highlights the inclusion of performing arts occupations on the temporary shortage list and what it means for international talent in the sector.

Learn more

Media mentions

Arts Professional: Creative Sector Must ‘Come Together’ to Give Artists Easier Access to Visas

Partner Louise Haycock highlights opportunities for easier access to overseas talent for the UK creative sector while guiding businesses through evolving visa rules.

Learn more

Blog post

British Citizenship for Adopted and Surrogate Children: What Families Should Know

Associate Amelia Haynes and Paralegal Clare Macmillan Bell discuss the legal considerations surrounding British citizenship for children born through adoption or surrogacy.

Learn more

Media mentions

Financial Times: Boom Time for Immigration Lawyers as US and UK Tighten Restrictions

Partner Bo Cooper provides insight on how evolving US and UK immigration policies, including recent H-1B changes, are shaping corporate mobility and compliance strategies.

Learn more

Video

Atividades Técnicas sob Status de Visitante | #MobilityMinute

O Diretor Executivo da Fragomen Brasil, Diogo Kloper, destaca uma atualização importante na política migratória brasileira, que muda significativamente o que estrangeiros podem fazer no país sob o status de visitante.

Learn more

Media mentions

Global Mobility Lawyer: Founders Without Frontiers: Navigating Immigration Rules for Start-Ups

Partner Rajiv Naik provides insight on how immigration frameworks across the UK, Europe and EMEA are evolving to support start-ups and entrepreneurial talent.

Learn more

Media mentions

The New York Times: Visiting the European Union? Expect to Give Your Biometric Data.

Partner Jo Antoons discusses the rollout of the EU's new Entry/Exit System.

Learn more

Media mentions

The Times: Bye bye, Dubai: why families are heading for Abu Dhabi

Fragomen is featured in The Times as a key immigration adviser highlighting Abu Dhabi’s rising demand for golden visas, especially among UK nationals seeking long-term, self-sponsored residency.

Learn more

Video

Important Update for Brazil-Bound Visitors | #MobilityMinute

Brazil Managing Partner Diana Quintas highlights Brazil’s visitor visa rules and what travelers should know.

Learn more

Blog post

Changes to Skilled Worker Dependants: How UK Government’s July 2025 Rules Affect Tech Talent

Senior Manager Kinka Tonchev and Paralegal Emily Whalley discuss how upcoming UK visa changes will affect skilled worker dependants and reshape tech sector mobility.

Learn more

Fragomen news

Partner Marius Tollenaere Contributes to Third Edition of Einwanderungsrecht

Partner Marius Tollenaere provides key insights on labour migration, procedures and employer obligations in the latest edition of "Einwanderungsrecht".

Learn more

Video

Oman Introduces a Golden Visa Program | #MobilityMinute

Manager David Makau discusses Oman's recent introduction of a Golden Visa program.

Learn more

Media mentions

The Stage: Actors, Dancers and Writers Set to Escape Visa Ban

Partner Louise Haycock highlights the inclusion of performing arts occupations on the temporary shortage list and what it means for international talent in the sector.

Learn more

Media mentions

Arts Professional: Creative Sector Must ‘Come Together’ to Give Artists Easier Access to Visas

Partner Louise Haycock highlights opportunities for easier access to overseas talent for the UK creative sector while guiding businesses through evolving visa rules.

Learn more

Blog post

British Citizenship for Adopted and Surrogate Children: What Families Should Know

Associate Amelia Haynes and Paralegal Clare Macmillan Bell discuss the legal considerations surrounding British citizenship for children born through adoption or surrogacy.

Learn more

Media mentions

Financial Times: Boom Time for Immigration Lawyers as US and UK Tighten Restrictions

Partner Bo Cooper provides insight on how evolving US and UK immigration policies, including recent H-1B changes, are shaping corporate mobility and compliance strategies.

Learn more

Video

Atividades Técnicas sob Status de Visitante | #MobilityMinute

O Diretor Executivo da Fragomen Brasil, Diogo Kloper, destaca uma atualização importante na política migratória brasileira, que muda significativamente o que estrangeiros podem fazer no país sob o status de visitante.

Learn more

Media mentions

Global Mobility Lawyer: Founders Without Frontiers: Navigating Immigration Rules for Start-Ups

Partner Rajiv Naik provides insight on how immigration frameworks across the UK, Europe and EMEA are evolving to support start-ups and entrepreneurial talent.

Learn more

Media mentions

The New York Times: Visiting the European Union? Expect to Give Your Biometric Data.

Partner Jo Antoons discusses the rollout of the EU's new Entry/Exit System.

Learn more

Media mentions

The Times: Bye bye, Dubai: why families are heading for Abu Dhabi

Fragomen is featured in The Times as a key immigration adviser highlighting Abu Dhabi’s rising demand for golden visas, especially among UK nationals seeking long-term, self-sponsored residency.

Learn more

Video

Important Update for Brazil-Bound Visitors | #MobilityMinute

Brazil Managing Partner Diana Quintas highlights Brazil’s visitor visa rules and what travelers should know.

Learn more

Blog post

Changes to Skilled Worker Dependants: How UK Government’s July 2025 Rules Affect Tech Talent

Senior Manager Kinka Tonchev and Paralegal Emily Whalley discuss how upcoming UK visa changes will affect skilled worker dependants and reshape tech sector mobility.

Learn more

Fragomen news

Partner Marius Tollenaere Contributes to Third Edition of Einwanderungsrecht

Partner Marius Tollenaere provides key insights on labour migration, procedures and employer obligations in the latest edition of "Einwanderungsrecht".

Learn more

Stay in touch

Subscribe to receive our latest immigration alerts

Subscribe

Our firm

  • About
  • Careers
  • Firm Governance
  • Media Inquiries
  • Recognition

Information

  • Attorney Advertising
  • Legal Notices
  • Privacy Policies
  • UK Regulatory Requirements

Our firm

  • About
  • Careers
  • Firm Governance
  • Media Inquiries
  • Recognition

Information

  • Attorney Advertising
  • Legal Notices
  • Privacy Policies
  • UK Regulatory Requirements

Have a question?

Contact Us
  • LinkedIn
  • Youtube
  • Instagram
  • Facebook
  • Twitter

© 2025 Fragomen, Del Rey, Bernsen & Loewy, LLP, Fragomen Global LLP and affiliates. All Rights Reserved.

Please note that the content made available on this site is not intended for visitors / customers located in the province of Quebec, and the information provided is not applicable to the Quebec market. To access relevant information that applies to the Quebec market, please click here.