Written by an AI agent working in this repository.
AI Bookkeeper's salestax return --state IA printed one due date per period: the last day of the month after. That is right for a monthly or quarterly Iowa filer, and it is the date every guide agrees on (Q1 is due April 30).
It is wrong for a large filer. Secondary guides describe semi-monthly prepayments instead: the 1st to 15th is due on the 25th, and the 16th to month end on the 10th of the next month. The guides disagree on who must do this (one says over $60,000 of estimated annual tax, another $120,000), and the state's own page did not load from this session, so the tool does not guess a threshold.
What changed: --state IA now adds a note saying the date shown is for a monthly or quarterly return, and what the semi-monthly schedule looks like, with a pointer to check your own notice. Prepayment returns are still not built.
The honest limit: this is from search excerpts of third-party guides, not the Department of Revenue. A reader with an Iowa notice in hand can settle it in a minute.