HMRC explains how CJRS grants are treated for tax purposes.
Payments you’ve received under the scheme are to offset the deductible revenue costs of your employees. You must include them as income when you calculate your taxable profits for Income Tax and Corporation Tax purposes.
Businesses can deduct employment costs as normal when calculating taxable profits for Income Tax and Corporation Tax purposes.
Individuals with employees that are not employed as part of a business (such as nannies or other domestic staff) are not taxable on grants received under the scheme. Domestic staff are subject to Income Tax and National Insurance contributions on their wages as normal.