Associated Companies: How They Affect Corporation Tax

If you have more than one company, the "associated companies" rules may affect your corporation tax rate. Associated companies divide the profit thresholds for the small profits rate.

Why Associated Companies Matter

Corporation tax uses tiered rates:

Profit LevelRate
Up to £50,00019% (small profits)
£50,001-£250,00019-25% (marginal relief)
Over £250,00025% (main rate)
With associated companies: These thresholds are divided by the number of associates + 1.

How Thresholds Change

Number of AssociatesLower LimitUpper Limit
0 (standalone)£50,000£250,000
1£25,000£125,000
2£16,667£83,333
3£12,500£62,500
4£10,000£50,000
Formula: Threshold ÷ (number of associates + 1)

What Makes Companies "Associated"?

The Definition

Two companies are associated if:

  • One controls the other, OR
  • Both are under common control

Control Means

Having control of:

  • More than 50% of ordinary share capital, OR
  • More than 50% of voting rights, OR
  • Rights to more than 50% of distributable income, OR
  • Rights to more than 50% of assets on winding up

Counting Associated Companies

Who Counts

Counts as AssociatedDoesn't Count
Companies you controlCompanies you have small stakes in
Companies controlled by same personsCompanies with different controllers
Group companiesJoint ventures (usually)

The "Same Persons" Test

Companies controlled by the same individual(s) are associated, even if:

  • They do different things
  • They have no transactions between them
  • They have different directors

Example 1: Clear Association

Person A owns:

  • Company X: 100%
  • Company Y: 100%
Result: X and Y are associated. Thresholds divided by 2.

Example 2: Multiple Owners

Person A owns:

  • Company X: 60%
  • Company Y: 60%
Result: Associated. A controls both (over 50% each).

Example 3: Not Associated

Person A owns Company X: 100% Person B owns Company Y: 100%

Result: Not associated (different controllers).

Family and Connected Persons

Attribution Rules

Shares held by certain "connected persons" may be attributed to you:

ConnectionAttribution?
Spouse/civil partnerYes
Minor childrenYes
Business partnersSometimes
Other relativesGenerally no
AssociatesSometimes

Example: Spouse Attribution

You own Company X: 100% Your spouse owns Company Y: 100%

Without attribution: Not associated With attribution: May be associated

Important: Attribution only applies for the associated company test if there's a "substantial commercial interdependence."

Substantial Commercial Interdependence

When It Applies

Attribution only connects family companies if they have:

  • Financial interdependence (loans, guarantees)
  • Economic interdependence (same customers, suppliers)
  • Organisational interdependence (shared management, premises)

Example: Truly Separate

You: Own a web design company Your spouse: Owns a cafe

If there's no commercial connection, attribution may not apply. Seek professional advice.

Dormant Companies

Do They Count?

Yes, but...

A dormant company counts as associated UNLESS:

  • It has no assets, OR
  • It hasn't carried on a trade since being incorporated
Many holding companies count because they hold shares in subsidiaries (those are assets).

Practical Examples

Example 1: IT Contractor

Situation: You have one company, no others Associates: 0 Lower threshold: £50,000 Upper threshold: £250,000

Example 2: Multiple Businesses

Situation: You own two trading companies Associates: 1 Lower threshold: £25,000 Upper threshold: £125,000

Tax impact: If each company makes £40,000:

  • Without association: 19% rate
  • With association: Marginal relief zone (higher effective rate)

Example 3: Group Structure

Situation: Parent company + 3 subsidiaries Associates: 3 Lower threshold: £12,500 Upper threshold: £62,500

Impact on Tax

Tax Calculation Example

Without associated companies:

  • Profit: £100,000
  • Rate: Marginal relief zone
  • Effective rate: ~19.4%
  • Tax: ~£19,400
With 1 associated company:
  • Profit: £100,000
  • Rate: Above £125k threshold = closer to 25%
  • Effective rate: ~22.8%
  • Tax: ~£22,800
Difference: ~£3,400 extra tax

Frequently Asked Questions

Do joint ventures count?

Usually not. Joint ventures where no single party has control aren't associated. But check the specific arrangements.

What about companies I'm a director of but don't own?

No association. Being a director doesn't create control.

Do associated companies share the threshold?

No. Each company gets the full (reduced) threshold. The threshold isn't shared between them.

What if associates are overseas?

Overseas companies can count as associated. The test is control, not location.

Does this affect dormant companies?

Dormant companies still count in the number unless they have no assets. Even a company with £100 in the bank counts.

Can I restructure to avoid this?

Potentially, but HMRC has anti-avoidance rules. Any restructuring must have genuine commercial reasons.

Summary

FactorImpact
What countsCompanies under common control
EffectThresholds divided by (associates + 1)
FamilyAttribution rules may apply
DormantCount unless no assets
PlanningLimited—anti-avoidance applies
Understanding associated companies ensures you apply the correct tax rate.


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