An employer conducted an audit of its workforce to ensure that it had documents confirming each employee's right to work in the UK. This was important to allow the employer to avoid liability for a civil penalty if it was found to have employed someone who did not have the relevant right to work in the UK.

After the audit, Mr Baker was asked to provide one of a list of documents that would demonstrate his right to work. After some delay he obtained a passport and provided this to his employer, but the employer was advised by the Home Office that although the employee had the right to live and work in the UK, the passport was not sufficient evidence of this. The employee was ultimately dismissed because he failed to provide his employer with satisfactory evidence.

The EAT overturned the tribunal's finding that the dismissal was because of illegality and fair. The employee had the right to live and work in the UK. As the employer would not have committed an offence had it continued to employ him, illegality could not be the reason for his dismissal.

However, the employer could rely on its genuine but mistaken belief that it would commit an offence if it continued to employ the employee without having evidence of his right to work. A dismissal in those circumstances could be for some other substantial reason. Whether such a dismissal would be fair would depend on the reasonableness of the employer's belief. This would in turn depend on what information the employer had given the Home Office and the advice it had been given. The question of fairness was remitted to the tribunal.