Repair 1: the missing holding
A BV (besloten vennootschap, a Dutch private limited company) with the shares in your own name can usually be restructured through a share merger. You set up a holding and contribute the shares to it. Under the right tax facility, this step is tax free at that moment. If the holding sells the company soon after this step, the tax office can treat the share merger as tax avoidance and tax it after all.
Do this repair well before any sale. See selling your channel or brand for its value.
Repair 2: rights in your own name
You can transfer trademarks, domains and copyrights in your own name to the company. The value must be one you can defend. While the brand is still small, the valuation takes little work. If the brand already has real value, the transfer itself becomes a taxable event. See stage name and legal name for the reasons.
Repair 3: the address
Changing the visiting address is administratively simple: a change in the trade register, new invoice templates, updated bank and contract records. The earlier version stays visible in the register history. The repair limits what happens next, and the past stays as it was. Options are in deciding your address.
Repair 4: a loan that became too large
You can borrow money from your own company up to €500,000. Up to that amount, the loan is outside box 2 (the Dutch tax on income from your own company's shares). Above that limit, the excess is treated as a distribution, measured at the end of the year. Bring the balance back under the limit before the end of the year, or convert part of it into a dividend on purpose. This way, you choose the outcome yourself.
Repair 5: understated income in earlier years
If you declared too little income in earlier years, you can make a voluntary disclosure. The sooner you do this, the better the result. See the way back.
The order
Start with the holding, because of the waiting period. Then transfer the rights, bring the loan balance down before the end of the year, change the address and correct earlier years. A lower customary salary is allowed if comparable work pays less, or for up to three years while a new BV is still unable to pay the full salary. The lower salary is what saves tax. At €36,000 compared with €58,000, you keep about €7,100 a year more. After a later dividend, about €2,800 of that remains. The loan gives you access to money, but your tax stays the same. Calculate it with your own figures. See start here for the design of the whole structure.