Citation work starts with an inventory, because you cannot correct what you have not found. We search for the business by every version of its name, by every phone number it has used, and by every address it has occupied, across the general directories, the map services, the industry and trade directories for what you do, the local chambers and business associations, and the data aggregators that feed all of them.
What comes back is usually a surprise: listings created automatically from public records, listings a former marketing company set up and abandoned, a profile a well-meaning customer started, and the old address living on in a dozen places. Each record is logged with what it says and where it disagrees with the truth.
The audit also finds what is missing — the directories your customers and your competitors actually use where you do not appear at all. For most trades that is a short list, and it is a different list for a dentist than for a roofer.
The free audit at the bottom of this page is a lighter version of this step, run by a person, and it tells you honestly whether the rest of the work is worth paying for.