Tax & Treasury Manager

Why this role exists

As PortSwigger grows, especially in global and enterprise markets, the opportunity to embed new policies and procedures around effective cash management becomes more prominent. Our exposure to foreign currency and counterparty risks also increases, necessitating an elevation of existing treasury policies and procedures as we expand.

Our tax footprint is expanding in complexity and scale. This creates a significant opportunity to ensure compliance and make strategic tax decisions.

We're looking for a Treasury and Tax Lead to take ownership of our tax responsibilities and treasury opportunities—someone who can balance deep technical expertise with commercial acumen, supporting international expansion and scalable financial operations. This role will be key to helping us scale sustainably and confidently as we grow our customer base, product offerings, and global presence.

What you'll be doingTax compliance & reporting

• Manage compliance across local and international obligations (corporate tax, sales tax, withholding, employment, etc.).
  
  
• Prepare or oversee tax filings, including US federal and state returns (with external partners), UK corporation tax, VAT, digital sales tax, and employment taxes.
  
  
• Own our US sales tax compliance using Vertex, and support integration with billing systems.
  
  
• Provide tax-related disclosures for statutory financial reporting, including deferred tax accounting.
  
  

Tax strategy & planning

• Develop and maintain transfer pricing documentation (e.g., software licensing, intra-group services, and intercompany agreements).
  
  
• Advise on the tax implications of product launches, pricing structures, international expansion, and support customer contract structuring to manage VAT/sales tax risk.
  
  
• Identify and support claims for tax reliefs such as UK R&D credits, patent box, and capital allowances.
  
  
• Monitor legislative changes globally, help shape IP and legal entity structuring, and proactively assess their impact on the business, developing strategies to support growth and efficiency.
  
  

Product & commercial enablement

• Support customer contract structuring to manage VAT/sales tax risk—especially across digital channels.
  
  
• Partner with Product and Engineering on tax engine configuration (Vertex/Avalara) in billing systems.
  
  
• Collaborate with Sales Ops to ensure quoting/pricing logic aligns with tax compliance.
  
  

Risk management & audit readiness

• Be the go-to person for treasury and tax authority audits and queries across all jurisdictions.
  
  
• Maintain internal controls and documentation to ensure audit-readiness.
  
  

Treasury management

• Own relationships with our banking partners, being the first point of contact and ensuring optimal service.
  
  
• Develop and maintain scalable treasury policies and procedures.
  
  
• Manage overall cashflow for the Group, assisting FP&A with projections and reporting.
  
  
• Work with FP&A to seek financial investment opportunities and generate returns.
  
  
• Introduce appropriate foreign exchange risk management processes and procedures.
  
  
• Maintain all banking compliance requirements and access.
  
  

Bring treasury and tax into the everyday

• Help make treasury and tax management clear, simple, and embedded in how we work.
  
  
• Be the go-to subject matter expert for all tax-related queries—from employment tax to sales tax and beyond.
  
  
• Improve visibility and confidence around tax liabilities and opportunities.
  
  

What success looks like

• Robust documentation around treasury and tax policies.
  
  
• Opportunities for increased returns on investment are sought.
  
  
• All tax filings are submitted on time and without issues.
  
  
• Stakeholders have confidence in cash projections and tax numbers and trust your judgment.
  
  
• We stay ahead of international exposure risks and turn them into opportunities.
  
  
• Tax becomes less of a black box and more of a strategic enabler.

Requirements
About you

• Previous experience in managing relationships with banks and formulating treasury policies and procedures.
  
  
• A sensible approach to risk management that dovetails into the organization's expansion plans.
  
  
• 3+ years of experience in sales tax compliance, specifically US or overseas (coupled with employment and business licensing).
  
  
• Confident with sales tax, VAT, and corporate tax, and familiar with tax software (bonus if you've used Vertex).
  
  
• Detail-oriented but pragmatic: comfortable rolling up your sleeves and getting things done.
  
  
• Curious and forward-thinking: keen to learn and evolve as PortSwigger grows.
  
  

Bonus if you have…

• Experience working with a global or SaaS business, or software licensing models.
  
  
• Involvement in R&D tax relief or IP structuring.

Benefits
Why join PortSwigger?

We're a team of curious, driven people working together to secure the web. Our culture is our superpower—collaborative, human, and focused on meaningful work. We provide an environment where you can do your best work, grow your expertise, and see the real-world impact of your contributions.

Read more about our culture and values on our Careers page.

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