Basis for filing
Why you are entitled to file: you use it, or you intend to.
US applications need a legal basis. Use in Commerce means you are already selling under the mark. Intent to Use means you have a genuine plan to. There are also bases founded on a foreign application or registration. The basis determines what evidence you must supply and when.
Why it matters to your application
Your basis decides what evidence you owe the USPTO and when - and, less obviously, how long your deadlines are. Applications filed under Section 1 or Section 44 get three months to answer an office action, extendable once. Madrid Section 66(a) applications get six months and cannot extend at all.
In order
- Decide whether you are already selling under the mark, or intend to.
- If you are selling across state or national lines, Use in Commerce is available and your registration can issue sooner.
- If you are not yet selling, Intent to Use secures the date now and defers the proof.
- If you hold a foreign application or registration, check whether a Section 44 or Madrid basis is available and what it changes about your deadlines.
How this plays out
Two applicants receive identical office actions on the same day. One filed under Section 1 and has three months plus an available extension. The other came in through Madrid and has six months and no extension - a difference nobody mentions until the deadline matters.
About basis for filing
Can I change my filing basis later?
In some circumstances, yes - most commonly converting intent-to-use to use in commerce once you start selling. It is not unlimited and carries its own requirements.
Which basis registers fastest?
Use in commerce, because the proof of use is already in the file. Intent-to-use adds a further step after approval.
Does my basis affect my deadlines?
Yes. It is one of the main things that changes how long you have to answer an office action, which is why the deadline cannot be worked out from the letter date alone.
General information about USPTO procedure, not legal advice about your situation. Always confirm the status and deadlines on your own application in USPTO TSDR.