Business details that appear incorrectly in Google results are extracted from Google local business pages, formerly Google places. Pre 2015 Google used to scrape websites that displayed business details and auto generate a business page for the business.
This practice has been stopped after businesses failed to claim their pages leaving hundreds of thousands of unclaimed business pages.
If your business details are being incorrectly displayed in Google, this may be a result of an auto generated page, or the business page was created by someone within the business but not updated, or a well meaning person added your business to Google Maps with outdated information, again this practice has also stopped and all edits need verifying now in Maps.
Correcting Business Details in Google
There are four ways you can correct your business details, depending on which way you decide, most will ultimately end up Google MapMaker where the details are checked before being changed.
I would strongly recommend that if the business page is not claimed and verified, then you should take this path to prevent this from happening again. Owning the business page allows you to brand it, manage it and view data insight from it.
Claim This Business:
If claim this business is visible in the knowledge panel in search or in the knowledge card in Google Maps, then the business is not verified. Click the link and proceed to claim the business.
Note: Click Verify Later
This will allow you to edit the business details. Once all the details are correct, you can then select Verify in the business page. You won’t be able to miss where to Verify the Page.
Suggest An Edit:
If the only button visible in the knowledge panel in search and knowledge card in Google Maps is: Suggest an Edit, then this page has been claimed and verified.
See: Claim Ownership
If you do have account details, you can log into your business page account and make changes within your business page.
Or log into your Google account and make direct edits within the knowledge panel itself.
See: Edit Knowledge Panel
If you still want to correct details but do not want to claim ownership, then click suggest an edit, correct the details and submit. These details will need to be verified within Mapmaker before they are changed.
Make sure the websites contact details reflect the new information or the edit is unlikely to be published.