Tuesday, 8:20 AM. An owner replies to the April statement you sent on the 6th. She has been comparing it to the year-to-date figure in your May cover note, and the two disagree by $640. You open April. It disagrees with itself too, because on the 14th someone entered a plumbing invoice dated April 28, exactly as the invoice said.
Nothing about that entry was wrong. The invoice was real, the date was the date on the paper, and the person entering it did what careful people do. The problem is older than the invoice: April was still open. An open month keeps accepting the past, and every reasonable edit it accepts moves a number that someone has already been given.
You have stopped noticing how often that happens, because each instance is small and each one is defensible. A payment recorded with last month's date because that is when it arrived. A reclass that made the expense lines tidier. A vendor credit applied to the invoice it belonged to. Individually they are housekeeping. Together they mean the statement you sent describes a version of April that no longer exists anywhere, including in your own system.
The cost lands in the owner's file, not yours. She now holds two Aprils and has to ask which one is right, and the honest answer, that both were right when produced, is not an answer an owner can use. It lands in your habits too: once a drifting month has caught you twice, you start marking statements preliminary, sending them later, or quietly re-running the report before you answer any question about it. That private re-checking is work, and it is the kind you cannot hand to anyone.
The slowest cost arrives in March, when the accountant asks about a number from August and the number has changed twice since the year-to-date report she is working from. Each change had a reason. None of the reasons were written down, because nothing asked for one.
A report you can still edit is not a record, just a draft with a date on it.
Here is what changes when a month ends twice: once on the calendar, and once when you lock it. After the lock, the late invoice is still real and it still gets booked. What it cannot do is slip into April unannounced. It becomes a decision with two correct answers: reopen April, with a reason on the record, and send a corrected statement that says so; or book it in May, where this month's statement carries it in the open. Both keep the number she holds true, or tell her plainly when it stopped being. The silent third option is gone.
The rest of the close gets lighter for the same reason. When a month cannot drift, the statement you sent is the statement, the year-to-date figure in your cover note matches it, and the question in March has an answer that agrees with the report the accountant is holding.
Scaalr treats a closed month as closed for every route into the ledger: a manual entry dated inside it is rejected, an import batch dated there is flagged before it saves, a scheduled entry due there is skipped and reported, and reopening the month requires a written reason, is recorded, and re-applies any card payments held while it was closed. The full checklist, from cut-off to lock to the year-end sweep, is in Month-End Close Checklist for Property Managers.
For the full close, what to finish before you lock a month and what year-end adds, see: Month-End Close Checklist for Property Managers.
The first 5 units are free, then $0.99 a unit a month, and period locks are on every plan.