A member of the EFS-Web listserv posted this question to the listserv earlier today:
His question is a very interesting question. Here is the answer.
In the old days, most patent applications were paper-filed rather than e-filed, and for the e-filings, USPTO assigned application numbers to the various e-filing processing workflows in blocks of 1000.
So a block of 1000 numbers would be given to the e-filed 371 cases (entries into the US national phase). And a block of 1000 numbers would be given to the e-filed 111a cases (continuations, divisionals, new domestic applications). Other than those two blocks, all of the numbers were allocated to the mail room where paper-filed cases where handled. It would take months or a year to use up a block of numbers for any of the e-filing workflows in those old days because e-filing was rare.
Nowadays of course the rare activity is the paper filings. About 98% of patent applications in USPTO are now e-filed.
But the distribution of work between the two e-filed workflows (371 and 111a) is extremely asymmetric. There are half a million 111a cases filed per year. In contrast there are only about 35K 371 cases filed per year.
I think nowadays the application numbers are probably assigned in blocks of 10K. This would mean that the 111a workflow uses up a block per week. In contrast the 371 workflow takes four or five months to use up a block.
So at any given instant, the block of numbers in current use for 371 cases is anywhere from a month to five months older than the block of numbers in current use for 111a cases.
So it is no surprise at all that a person could file a 371 case and a 111a case on the same day, and the application number given to the 371 case would be a much smaller number than the number given to the 111a case. For example one day in July we filed a 111a case and the application number that EFS-Web gave to us was 15/219,xxx and on the same day we filed a 371 case and the application number that EFS-Web gave to us was 15/114,xxx.
Similarly it is no surprise that your new 371 case application could have a number that is much smaller than the number you received a couple of months ago on a 111a case.
I know almost nothing about patents, and I loved this explanation.
This application number information may seem inconsequential to most. However, for those who continually deal with the minutia of working with the the USPTO, this small insight is invaluable. This just further underscores the value of this blog.