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 protected]

T:+44 (0)207 090 9272

F:+44 (0)207 090 9101

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Fragomen LLP

1st Floor, 95 Gresham St,

London EC2V 7NA

United Kingdom

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  • English

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[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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Get in touch

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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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

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Senior Associate Arta Djahanschiri and Associate Iris Barthel discuss how EU-Turkey Association Law, including Association Council Decision No. 1/80, can provide Turkish employees and their family members in Germany with residence and labor market rights that may extend beyond protections available under the German Residence Act.

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Do You Need a Visa for Thailand? Tourist Visa Rules Explained

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In this Hong Kong Business article, Managing Director Magdalene Tennant discusses Hong Kong’s recent decision to allow employment and dependent visa renewal applications to be filed up to three months before expiry, a change intended to reduce the risk of work disruptions and provide employers with greater flexibility in managing foreign talent.

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Irish Examiner: Updates to Non-EU Work Permits Will Help Firms Fill Critical Roles

Practice Leader Colm Collins explains how Ireland's employment permit updates can help employers address workforce shortages while strengthening the country's ability to attract global talent.

Learn more

Blog post

Understanding EU-Turkey Association Rights for Workers and Families in Germany

Senior Associate Arta Djahanschiri and Associate Iris Barthel discuss how EU-Turkey Association Law, including Association Council Decision No. 1/80, can provide Turkish employees and their family members in Germany with residence and labor market rights that may extend beyond protections available under the German Residence Act.

Learn more
Generic Insights

Media mentions

Deutscher AnwaltSpiegel: Internationale Rekrutierung ist eine Compliancefrage

Partner Marius Tollenaere and Associate Jamela Sharrock examine how employers in Germany can strengthen immigration compliance by embedding it into every stage of the employment lifecycle.

Learn more

Podcast

EB5: What Prospective Applicants Need to Know NOW!

In this episode of The Immigration Conversation, Partner Chad Blocker, Senior Counsel Mitchell Wexler and Associate Alex Kim discuss what prospective EB-5 applicants should know now, including source-of-funds documentation, project selection, concurrent filing, retrogression and upcoming program deadlines.

Learn more

Blog post

New EU Social Security Coordination Rules: What Employers Need to Know

In this blog, Partner Jo Antoons and Senior Manager Marina Ocariz discuss the EU’s provisional agreement on revised social security coordination rules and what employers should know about the expected changes to A1 certificate requirements, posted worker rules and short-term cross-border work compliance.

Learn more

Blog post

Approaching EB-5 Grandfathering Deadline: What Investors Need to Know Before September 30, 2026

In this blog, Partner Rahul Soni explains the EB-5 grandfathering provisions under the EB-5 Reform and Integrity Act of 2022 and why prospective investors should consider filing before the September 30, 2026 deadline to help preserve statutory protections and reduce exposure to future program uncertainty.

Learn more

Video

Do You Need a Visa for Thailand? Tourist Visa Rules Explained

In this video, Practice Leader Kate Praphakornphiphat explains the key requirements, documents, fees and processing time for a Thailand tourist visa, as well as stay duration and extension options for short-term travel. 

Learn more

Fragomen news

Fragomen and Talent Beyond Boundaries Named Co-Chairs of Global Task Force on Refugee Labour Mobility

Fragomen and Talent Beyond Boundaries announce that they will jointly serve as co-chairs of the Global Task Force on Refugee Labour Mobility for a two-year term beginning in June 2026.

Learn more

Blog post

From Barnsley to the North: AI Growth and the UK's Immigration Challenge

In this blog, Manager Gillian Gibbons and Immigration Consultants Gemma Oliver and Larna Kate Hadfield examine how Barnsley’s designation as the UK’s first government-backed Tech Town reflects wider AI and digital growth across the North of England, and why immigration strategy will be critical for employers seeking to access the global talent needed to support regional innovation.

Learn more

Media mentions

Hong Kong Business Magazine: Employers Seek Broader Immigration Reforms

In this Hong Kong Business article, Managing Director Magdalene Tennant discusses Hong Kong’s recent decision to allow employment and dependent visa renewal applications to be filed up to three months before expiry, a change intended to reduce the risk of work disruptions and provide employers with greater flexibility in managing foreign talent.

Learn more

Media mentions

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In this article published by Professional Engineering, Senior Manager Nadine Barnole examines how UK engineering employers can continue to access international talent amid growing skills shortages and a rapidly evolving immigration landscape.

Learn more

Media mentions

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In this Times Brasil CNBC Real Tech interview, Partner Diana Quintas discusses Brazil’s recent visa exemption for Chinese nationals, what it signals for Brazil-China mobility and how technology is helping support more efficient cross-border movement.

Learn more
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Important Updates
Important Updates
June 25, 2026 | CanadaCanada: Quebec to Reopen Family Sponsorship Applications Under New Intake Caps
June 26, 2026 | IrelandIrish Examiner: Updates to Non-EU Work Permits Will Help Firms Fill Critical Roles
June 26, 2026 | KuwaitKuwait: Relaxed Employer Transfer Rules in Limited Circumstances
June 26, 2026 | 🌐Minimum Salary Changes Announced
June 26, 2026 | 🌐Worldwide: Temporary Ebola-Related Entry Restrictions Introduced
June 25, 2026 | CanadaCanada: Quebec to Reopen Family Sponsorship Applications Under New Intake Caps
June 26, 2026 | IrelandIrish Examiner: Updates to Non-EU Work Permits Will Help Firms Fill Critical Roles
June 26, 2026 | KuwaitKuwait: Relaxed Employer Transfer Rules in Limited Circumstances
June 26, 2026 | 🌐Minimum Salary Changes Announced
June 26, 2026 | 🌐Worldwide: Temporary Ebola-Related Entry Restrictions Introduced
June 25, 2026 | CanadaCanada: Quebec to Reopen Family Sponsorship Applications Under New Intake Caps
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