Understanding UK Tax for Global Founders and Startups | Onside Accounting

What are the key challenges you might face?

Expanding internationally? Many UK startups are hiring talent from across the globe and attracting investment from overseas. But with that global reach comes a new level of tax complexity. The interaction between international tax rules and the UK system can be challenging, particularly for founders, investors and globally mobile employees.

Our latest Onside Factsheet Understanding UK Tax for Global Founders and Teams explains the key tax rules and upcoming changes that may affect you. Download your copy today.

Key UK Tax Changes for 2025: What Founders Need to Know

From April 2025, the UK is introducing major reforms that will impact international founders, non-domiciled individuals, and mobile teams:

• The remittance basis is ending

• A new Foreign Income and Gains (FIG) regime will apply to all UK residents

• Overseas Workday Relief (OWR) rules are changing for qualifying new residents

These changes affect how foreign income and gains are taxed, how residency is determined, and how cross-border work is treated under PAYE.

What’s Inside Our Factsheet

Our comprehensive guide breaks down the main issues every internationally focused startup should understand:

• Statutory Residence Test (SRT): How your UK tax status is determined and why it matters

• Foreign Income and Gains (FIG) regime: The new post-remittance-basis framework for non-domiciled individuals

• Reliefs and exemptions: Including Overseas Workday Relief for qualifying newcomers to the UK

• Company residency rules: How central management and control determine where your business is tax-resident

• Practical payroll considerations: When to apply PAYE for international employees.

Why It Matters for Startups Expanding Globally

The shift toward global hiring and remote work means more founders are becoming internationally mobile - living in one country, operating in another and attracting investment worldwide. Understanding UK tax residency and cross-border rules can help avoid double taxation, compliance risks and unexpected costs.

At Onside Accounting, we specialise in helping tech startups and scale-ups navigate these complexities - from structuring your company for international growth to ensuring tax compliance across jurisdictions.

Stay Ahead with Onside

Our expert team provides accounting and tax advisory support to help founders, CFOs, and global teams make confident decisions.