Businesses must always issue an invoice when they provide services that entitle the buyer to claim a deduction for home improvement services or household services. Invoices must meet the general requirements, and must include the business’s VAT registration number (CVR/SE no.).
In order to get a deduction, your customers will also need a labour cost specification. We recommend that labour costs are stated excluding VAT.
For services such as cleaning and window cleaning, all costs are considered labour costs if materials costs make up less than 2%.
You only need to issue one invoice even if the costs are split between several people in a household and they each get a deduction for different parts of the costs.
Read about VAT