An overseas assignment can affect both Income Tax and National Insurance. They have different rules, and the answer for one does not automatically determine the other.
Review the proposed arrangement before departure, including where the employee will work, the expected duration and their continuing UK connections.
Income Tax and residence
The employee’s residence position and where duties are performed affect the tax analysis. Working abroad for a stated period does not by itself prove that overseas earnings are outside UK tax.
Use the current UK residence guidance and review visits and work undertaken in the UK. The host country may also tax the earnings, making local advice important.
Payroll instructions
Establish how UK payroll should operate and whether HMRC needs information or an application. Do not stop deductions simply because an employee has moved abroad.
Keep the expected arrangements under review if the assignment changes or the employee returns earlier than planned.
National Insurance and overseas contributions
The destination, employment arrangement and applicable social security agreement can affect where contributions are due. Certificates and other evidence may be needed.
Check the official guidance for employees working abroad. Any voluntary contributions should be considered against the person’s actual contribution record and current eligibility, rather than an assumed pension entitlement.