Through what feels like a clever loophole, but really is just common sense, there is a way to file a patent application one day and pay the filing, exam, and search fees another day without incurring any surcharges.
Typically, if you pay those filing fees after filing, you’ll have to pay a surcharge of $140 (for large entities as of this writing). Best practices therefore dictate that you pay the filing fees contemporaneously with an initial filing of a patent application. I’ve never been in a situation where I didn’t want to pay the filing fees immediately after filing the application, though I can envision a few very particular situations in which you might strategically do this.
Intentional non-payment aside, sometimes you may not be able to pay the filing fees. The Patent Office’s payment system – Revenue Accounting and Management, or RAM – sometimes goes down for maintenance, and sometimes for unexpected reasons. Extreme caretakers would check to see if RAM was up before lodging an application. However, because you pay for a filing after making the filing, there would still be the possibility that RAM goes down after you check, while you’re filing, and before you’ve paid. In that situation, you’ll likely incur the surcharge. An exception is if you are filing late at night. If you’ve lodged the application in the wee hours in Alexandria (as one on the East Coast can easily do at 9 or 10pm), you can go to sleep, wake up, and pay the fees the next day. Because your application will receive a filing date post-midnight, the filing fees can still be paid on the filing date, even though they weren’t filed contemporaneously.
I called the Patent Office to confirm this, and they agreed. One representative in the Revenue Accounting Department did note, however, that the payment would still need to be received by 1:45pm EST lest it be timestamped the next day. I couldn’t get her to explain why, so if you adopt a strategy as above – which I really can’t recommend – get that payment in early after waking up.