It’s very common for a business owner to have made purchases before the business was officially up and running. This isn’t a problem at all. They should definitely still be on the books and it’s a simple journal entry between the proper expense account(s) and the owner’s contributions account. As the owner, you can make cash contributions to the company to get it started and count legitimate business expenses such as office supplies, equipment (such as a laptop, tools, etc.), the domain name, and any other legitimate business expenses. Just keep all the receipts. So don’t hesitate to count every business expense you made before you officially got started.