We have a customer who is registered with Sunbiz as an LLC but it is a sole member LLC. Since it's a sole member LLC the titling should be John Smith, DBA Apple LLC. There is no fictitious name filing on Sunbiz. Is one needed in this case? My thoughts are no because the DBA is registered as a sole member LLC.

It should be registered with the state...IMHO it's not a fictitious name, it's a legal name. I'm also not sure that the title of the account needs to include the person's name, our single member LLC was in just that...the businesses name.

Ah, I found an exception. If the solemember elects to use his SSN instead of an EIN, would be titled as you suggest.

Actually, the listing I'm looking at lists it in this manner:

John Doe, Doe's Auto Parts, LLC. Sole proprietorships list the way you have shown above.

Often, the single member's name is used in the account styling if the single member's SSN is used (the LLC elects to be disregarded by the IRS as an entity). I would not use a "DBA" setup to do so.

I think there are two reasonable stylings that address what you are trying to accomplish:

John Smith, Sole Member
Apple LLC

Apple LLC (with a tax reporting name set up as John Smith)

The latter option assumes your system can allow you to designate a tax reporting name that is not part of the account styling.

You didn't ask, but let me suggest a cautionary note: While it is correct for the LLC to use its sole member's SSN and for you to record that number as the TIN for the LLC, don't let that confuse your staff concerning the ownership of the account. The owner is not John Smith. It is Apple LLC. For example, if a levy comes in in John Smith's name and with his SSN, the Apple LLC account should not be reached by the levy even if the account is styled with Smith's name and uses his SSN. Smith and the LLC are two separate legal persons.

...an addendum to John's observations. If the name of the LLC contains the surname of the sole member:

Smith, LLC

then there is no need to reference "DBA" or "sole member" in the account title. Whatever titling format you use, all you are trying to do is provide the IRS with "SMIT" somewhere in the account title so it will match with the SSN.