Financial planning falls in Class 36, finance & insurance. Everything below is read from the USPTO's own list of accepted descriptions, not from an opinion about where it belongs.
Searching the USPTO Trademark ID Manual for financial planning returns 37 accepted descriptions, and all of them sit in Class 36. The manual is the list of identifications the office has already approved, so wording taken from it is pre-approved and settles the class at the same time.
The class follows from the identification you write, so "what class am I in" is really "what exactly do you sell". How the class system works covers the rest.
Banking, insurance, investing, real estate, or other money services.
37 accepted descriptions in the manual mention financial planning. For example:
Financial planning is a service, so it sits in Classes 35 to 45. Software that delivers a service is often Class 9 or Class 42 as well.
Finance, insurance and real estate: insurance underwriting and real estate brokerage are here. Software that does the same job is a good, not a financial service: downloadable software is Class 9.
The class decides what a registration covers; it does not decide whether the name is available. Relatedness is judged on the identifications, so a conflict can sit in a class you never looked at: the same name in a different industry.
Check whether your name is clear for financial planning Searches the live USPTO register, including sound-alike and meaning-alike names. First search $2, then $5.Financial planning sits in Class 36, finance & insurance. That is where the USPTO's own ID Manual puts it: 37 accepted descriptions mentioning financial planning fall in Class 36.
You file in every class you actually use the mark in, and the USPTO charges its fee per class. Selling a product and also running an online store for it is two classes, not one. Filing in classes you do not use is worse than filing in too few: an application has to be supported by real use or a genuine intent to use.
No. The class decides what a registration covers. Availability turns on whether someone already holds a similar mark for related goods, and relatedness is judged on what the identifications say rather than on the class number, so marks in different classes can still conflict.
Not what you sell? Search the class finder for your own wording, or browse all 45 classes.