William Diaz

Senior Manager

William Diaz

William Diaz
William Diaz
  • People

Senior Manager

William Diaz

Country / Territory

  • United KingdomUnited Kingdom

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Languages

  • 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

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

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
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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

Explore more at Fragomen

Article

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

Fragomen on immigration

Business Immigration After the Midterms (Part 1): What to Expect No Matter What

Partner K. Edward Raleigh analyzes how post‑midterm US business immigration will shift toward heightened enforcement, worker‑protection scrutiny and cross‑agency oversight, urging employers to align hiring practices, sponsorship decisions and documentation with consistent, defensible workforce strategies.

Learn more

Media mentions

Business Insider: Trump’s Green Card Memo Dropped Before a Holiday Weekend. Immigration Lawyers Say Clients Panicked.

Counsel Brian Hunt said employers quickly sought clarity after a USCIS memo on green card adjustment of status raised questions about immigration timelines, work continuity and travel planning.

Learn more

Awards

Fragomen named “Law Firm of the Year” for Immigration Law by Best Law Firms™ - Australia

Fragomen is named “Law Firm of the Year” for Immigration Law by Best Law Firms™ - Australia and receives National and Regional Tier 1 rankings in Immigration Law.

Learn more

Media mentions

USA Today: USCIS Green Card Announcement Spurs Confusion. What to Know

Partner Parisa Karaahmet discusses the broad application of a USCIS memo to adjustment of status applicants and notes that H- and L-visa holders may have a somewhat easier burden in demonstrating factors that support favorable discretion.

Learn more

Article

Commonwealth Games 2026 Travel Planning: UK ETA Rules for Teams and Fans

Senior Manager Alice Spaull and Associate Stephanie Fitton examine the evolving UK immigration and Electronic Travel Authorisation (ETA) requirements for athletes, their support teams and associated guests attending the Commonwealth Games 2026, highlighting key compliance risks and the importance of early travel planning.

Learn more

Media mentions

The Associated Press: Trump’s Latest Immigration Move Clouds the Path to Green Cards

Partner Kevin Miner discusses the expected impact of new USCIS green card guidance on employment-based immigration, noting dual-intent visa cases would likely continue under business as usual with no significant impact.

Learn more

Media mentions

The Wall Street Journal: What to Know About the Trump Administration’s New Green Card Policy

Partner K. Edward Raleigh discusses a recent USCIS memo that appears to signal greater caution in how adjudicators assess adjustment of status cases rather than establishing a new legal standard.

Learn more

Fragomen news

2026年5月 アメリカ移民法ダイジェストLearn more

Video

Germany Health Insurance Requirements for Visas: What You Need to Know

Senior Manager Sumejja Handzo outlines Germany’s health insurance requirements for visas and residence permits, including coverage options, documentation considerations and key compliance requirements for foreign nationals relocating to Germany.

Learn more

Media mentions

ABA Journal: Will US Immigration Policies Create ‘Chilling Effect’ on World Cup?

Partner Daniel Schwarz highlights how US visa appointment backlogs and limited availability for B visas are shaping international travel planning for the upcoming World Cup.

Learn more

Article

Beyond Temporary Protection: Why Europe Needs Clear Exit Pathways

Knowledge Management Manager Annabelle Duchêne explores how Europe’s prolonged reliance on Temporary Protection Status has created legal and workforce uncertainty and why clear, structured exit pathways are now essential for employers and displaced individuals alike.

Learn more

Article

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

Fragomen on immigration

Business Immigration After the Midterms (Part 1): What to Expect No Matter What

Partner K. Edward Raleigh analyzes how post‑midterm US business immigration will shift toward heightened enforcement, worker‑protection scrutiny and cross‑agency oversight, urging employers to align hiring practices, sponsorship decisions and documentation with consistent, defensible workforce strategies.

Learn more

Media mentions

Business Insider: Trump’s Green Card Memo Dropped Before a Holiday Weekend. Immigration Lawyers Say Clients Panicked.

Counsel Brian Hunt said employers quickly sought clarity after a USCIS memo on green card adjustment of status raised questions about immigration timelines, work continuity and travel planning.

Learn more

Awards

Fragomen named “Law Firm of the Year” for Immigration Law by Best Law Firms™ - Australia

Fragomen is named “Law Firm of the Year” for Immigration Law by Best Law Firms™ - Australia and receives National and Regional Tier 1 rankings in Immigration Law.

Learn more

Media mentions

USA Today: USCIS Green Card Announcement Spurs Confusion. What to Know

Partner Parisa Karaahmet discusses the broad application of a USCIS memo to adjustment of status applicants and notes that H- and L-visa holders may have a somewhat easier burden in demonstrating factors that support favorable discretion.

Learn more

Article

Commonwealth Games 2026 Travel Planning: UK ETA Rules for Teams and Fans

Senior Manager Alice Spaull and Associate Stephanie Fitton examine the evolving UK immigration and Electronic Travel Authorisation (ETA) requirements for athletes, their support teams and associated guests attending the Commonwealth Games 2026, highlighting key compliance risks and the importance of early travel planning.

Learn more

Media mentions

The Associated Press: Trump’s Latest Immigration Move Clouds the Path to Green Cards

Partner Kevin Miner discusses the expected impact of new USCIS green card guidance on employment-based immigration, noting dual-intent visa cases would likely continue under business as usual with no significant impact.

Learn more

Media mentions

The Wall Street Journal: What to Know About the Trump Administration’s New Green Card Policy

Partner K. Edward Raleigh discusses a recent USCIS memo that appears to signal greater caution in how adjudicators assess adjustment of status cases rather than establishing a new legal standard.

Learn more

Fragomen news

2026年5月 アメリカ移民法ダイジェストLearn more

Video

Germany Health Insurance Requirements for Visas: What You Need to Know

Senior Manager Sumejja Handzo outlines Germany’s health insurance requirements for visas and residence permits, including coverage options, documentation considerations and key compliance requirements for foreign nationals relocating to Germany.

Learn more

Media mentions

ABA Journal: Will US Immigration Policies Create ‘Chilling Effect’ on World Cup?

Partner Daniel Schwarz highlights how US visa appointment backlogs and limited availability for B visas are shaping international travel planning for the upcoming World Cup.

Learn more

Article

Beyond Temporary Protection: Why Europe Needs Clear Exit Pathways

Knowledge Management Manager Annabelle Duchêne explores how Europe’s prolonged reliance on Temporary Protection Status has created legal and workforce uncertainty and why clear, structured exit pathways are now essential for employers and displaced individuals alike.

Learn more
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May 28, 2026 | AustraliaFragomen named “Law Firm of the Year” for Immigration Law by Best Law Firms™ - Australia
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May 29, 2026 | FranceFrance: EU Blue Card Rules Relaxed
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May 28, 2026 | United StatesBusiness Insider: Trump’s Green Card Memo Dropped Before a Holiday Weekend. Immigration Lawyers Say Clients Panicked.
May 28, 2026 | AustraliaFragomen named “Law Firm of the Year” for Immigration Law by Best Law Firms™ - Australia
May 29, 2026 | BermudaBermuda: New Work Permit Policy to Prolong Processing Times
May 29, 2026 | FranceFrance: EU Blue Card Rules Relaxed
May 29, 2026 | IrelandIreland: Occupation Lists Changes Published,“50:50” Rule Modification Proposed
May 28, 2026 | United StatesBusiness Insider: Trump’s Green Card Memo Dropped Before a Holiday Weekend. Immigration Lawyers Say Clients Panicked.
May 28, 2026 | AustraliaFragomen named “Law Firm of the Year” for Immigration Law by Best Law Firms™ - Australia
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