The HMRC Compliance Calendar: Key Dates for Contractor Management in 2026

Managing a contractor workforce in the engineering and manufacturing sector means staying on top of an ever-growing list of compliance obligations. With significant regulatory changes taking effect throughout 2026, organisations need a clear roadmap to navigate IR35 determinations, umbrella company oversight, minimum wage obligations, and the upcoming Employment Rights Bill changes.

This month-by-month guide focuses on the compliance deadlines that matter most for businesses managing contractors, helping you plan and avoid costly penalties.

The 2026 Compliance Calendar: Monthly Breakdown

April 2026

1st April - National Minimum Wage Increase

The National Living Wage will rise to £12.71 per hour for workers aged 21 and over, with substantial increases across all age bands. For organisations managing contractors through PAYE arrangements or temporary workers via umbrella companies, this matters significantly.

Action required:

• Review all PAYE contractor and temporary worker rates before 1 April
• Check umbrella company calculations account for the new rates
• Update rate cards and procurement systems
• Verify agency partners have updated their minimum rates

1st April - IR35 Status Review

Updated small company thresholds come into force, potentially reclassifying around 14,000 organisations as “small” for IR35 purposes. Where this applies, responsibility for IR35 status determinations moves back to the contractor’s personal service company (PSC). Businesses must be able to confirm their size on request and provide a response within 45 days. Click here to find out if your business is exempt.

Action required:

• Determine your company size classification under the new thresholds
• Review all existing Status Determination Statements (SDSs) for accuracy
• Update IR35 processes if your classification has changed
• Ensure contractors understand who holds determination responsibility
• Check that working practices align with stated IR35 status

6th April - Umbrella Company PAYE Rules

From 6 April 2026, recruitment agencies will become responsible for PAYE compliance on payments made to workers supplied through umbrella companies. This represents one of the most significant changes to the contractor supply chain in recent years. Click here to find out more.

Action required:

• Conduct due diligence on all umbrella companies in your supply chain before April
• Review agency contracts to ensure appropriate indemnities and compliance obligations
• Implement umbrella company verification processes
• Establish audit trails demonstrating proper PAYE compliance checks
• Consider whether your MSP or agency partners have robust compliance frameworks

October 2026

Employment Rights Bill

Sexual Harassment Prevention Duty

New duties on employers to prevent sexual harassment come into force, requiring organisations to take "all reasonable steps" to prevent harassment - including by third parties such as contractors and temporary workers. 

Action required:

• Extend anti-harassment policies to explicitly cover contractors
• Include contractors in workplace training programmes
• Update contracts to reflect harassment prevention obligations
• Establish reporting mechanisms accessible to contingent workers

Fire and Rehire Restrictions

New restrictions on fire and rehire practices come into effect, though with a more limited scope than originally proposed. The practice becomes automatically unfair for changes to certain core terms.

Action required:

• Review workforce planning strategies
• Consider implications for flexible resourcing models
• Update HR policies to reflect new restrictions

Ongoing Compliance: Year-Round Obligations

Quarterly IR35 Reviews

IR35 status isn't set-and-forget. Working practices evolve, and status determinations must reflect reality.

Best practice:

• Review SDSs quarterly or when working practices change
• Maintain documentation of actual working arrangements
• Respond promptly to contractor disagreements
• Keep detailed records to defend determinations during HMRC inquiries

Continuous Umbrella Company Monitoring

With joint and several liability for PAYE errors from April 2026, ongoing umbrella company oversight becomes critical.

Best practice:

• Verify umbrella company PAYE calculations monthly
• Check workers are receiving correct payslips with full transparency
• Monitor for warning signs (high take-home promises, frequent company name changes)
• Maintain audit trails of compliance checks performed

Agency Performance Management

Your agencies are now on the hook for PAYE compliance in umbrella arrangements from April 2026.

Best practice:

• Regular compliance meetings with agency partners
• Review agency due diligence processes
• Verify agencies have appropriate PI insurance
• Audit agency compliance documentation quarterly

The regulatory landscape for contractor management is complex and constantly evolving. By planning and understanding the key dates that matter, you can turn compliance from a burden into a competitive advantage - building a workforce model that's both flexible and fully compliant.

Get ahead of 2026's compliance challenges:

• Download our Complete Guide to IR35
• Read our Umbrella Compliance Guide
• Explore our 2026 Compliance Checklist

Contact us todayand explore our Payroll & Compliance solutionsto learn more about how we can help your organisation stay compliant while managing your engineering and manufacturing contractor workforce effectively.