TMEP § 819.05(a)
The trademark electronic filing system will require all filing fees and any applicable additional fees known at the time of filing. All filing fees and additional fees that are required at filing must be paid in order to submit the application.
Example: If an applicant files an application for two classes and only uses entries from the USPTO’s Acceptable Identification of Goods and Services Manual (ID Manual) within the electronic form, but elects not to provide its entity type, the system will require an insufficient information fee for each class in the application. The applicant must pay the filing fees for two classes and the insufficient information fee for two classes.
If the examining attorney determines that the initial application has not met the base application filing requirements and the trademark electronic filing system did not require the relevant insufficient information or free-form text ID fees, then the examining attorney must issue an Office action requiring the applicant to pay the additional fee(s).