You now need to pay the data protection fee.
The old regime of registration has been replaced with the requirement to pay the ICO a data protection fee unless you are exempt.
On payment, your business is added to the public register.
There are three different levels of fee, based on the risks associated with the personal data processing and depends on a variety of factors including how many members of staff you have and your annual turnover.
The ICO has started prosecuting businesses that are not paying the data protection fee.