The Tax Trap: Can You Lower Your Taxes by Splitting Income Between US and UK Companies?

By Viktoriia Korna — CEO, Corporatee
Last updated: March 19, 2026

Many international entrepreneurs make the same mistake. They set up a dual structure—for example, a UK Ltd to handle European operations and a US LLC for the American market—believing this will automatically lower their tax bill by spreading profits across different jurisdictions.
However, in 2026, the UK’s HM Revenue & Customs (HMRC) has become even stricter regarding what are known as "Associated Companies." If you fail to account for this rule at the start, your effective tax rate could skyrocket unexpectedly.

The UK operates a progressive Corporation Tax scale:

1. 19% (Small Profits Rate): Applied if a company’s taxable profits are £50,000 or less.
2. 25% (Main Rate): Applied if profits exceed £250,000.
3. Marginal Relief: In the gap between £50k and £250k, the tax is calculated using a complex formula where the effective rate on that specific slice of profit can reach 26.5%.

What’s the catch?
If you own both a UK company and a US LLC, HMRC considers them "Associated." This means the £50,000 and £250,000 thresholds are divided by the number of companies under your control.

The Result: If your UK company earned £40,000, you would normally pay 19%. But because you also own a US company, your threshold drops to £25,000. Now, a portion of your profit (£15,000) will be taxed at the higher marginal rate in the UK.

Even if you are a non-resident and your American company is registered in a "private" state like Wyoming or Delaware, tax authorities have several leverage points:

1. The Banking Trail: When opening accounts with Wise, Mercury, or Revolut, you use the same passport. Banks share beneficial ownership data under Anti-Money Laundering (AML) regulations.
2. The End of BOI Doesn't Mean Anonymity: While the US effectively scrapped the mandatory BOI reporting to FinCEN for domestic LLCs in March 2025, ownership data is still recorded by banks and registered agents. This information can be shared with HMRC upon request via bilateral tax treaties.
3. Intercompany Transactions: Any transfer of funds between your UK Ltd and US LLC (payments for software, marketing, or consulting) immediately flags the connection in bank statements.

To make this structure work for you instead of against you, follow these rules:

✅ Synchronize Fiscal Years. Set the same reporting period for your UK Ltd and US LLC. This simplifies calculating consolidated profits if the "Associated Company" rules are triggered.
✅ Document Everything. If one company pays the other, you must have a formal Service Agreement and a valid invoice. Without these, the tax office may reclassify the transfer as a "disguised dividend."
✅ Leverage "Dormant" Status. If one of your companies is inactive (dormant), it is not counted when dividing the UK tax thresholds. However, this must be declared correctly in your filings.
✅ Be Honest with Your Bank. Never hide the existence of a second company during a KYC check. Having your account frozen due to suspected "hidden structures" is far more expensive than any tax bill.

Contact us today for a free assessment of your proposed setup to ensure compliance with the 2026 Associated Company rules.