To avoid the hassle of getting a CodeSign cert under your own name (identity authentication may be a hassle), you can get a D-U-N-S number from Dun and Bradsheet (DnB) with a business name. The business name must not be fictitious and can be verified with a business registration authority.
If you apple to DnB direct, they will charge you a few hundred dollars. But if you through Apple at the link, you get it free:
DnB will call in about a week to verify. If they ask whether you are operating as a sole-proprietor, tell them you are at the moment and you are looking for partners. They will issue your business a D-U-N-S number within 2 days. Because you don't need a D-U-N-S number to register an Apple developer license if you are a sole proprietor.
With a D-U-N-S number, your application for CodeSign is almost done within a day or 2. Comodo does not do renewal, so upon every expiry is a new purchase.
Recently, I converted my Limited Liability Partnership (LLP) company to a sole-proprietor and I am saying this from 1-month-old experience. Even though I keep the same name (fictitious for explanantion) "MyComany LLP" to "MyCompany", address and phone number, DnB said that my business registration number is different so I have to get a new D-U-N-S. They advise me to get it free via Apple.