Behind on Your Books? Your Real Runway to the Extension Deadline

Back in April, filing an extension felt like a solution. Six more months, some breathing room, and a promise to sort the books out over the summer.

Then the summer happened.

It is now the last week of August, and the runway is shorter than most people think. If you file a partnership or S-corp return, your extended deadline is Tuesday 15 September — three weeks away. If you file as an individual or a C-corporation, it is Thursday 15 October — a little over seven weeks.

Those are very different situations, and the plan below is built for both. If your reconciliations stopped somewhere around March, you are not unusual and you are not out of time. But you do need to work in the right order.

First, be honest about what the extension bought you

An extension moved your filing date. It never moved your payment date.

Any balance owed on the 2025 return was due back in April, and interest has been accruing on it since. That shapes how you sequence the work: the fastest route to an accurate number is clean books, and every week the books stay messy is another week of interest on a figure nobody has calculated yet.

One more thing shares that 15 September date: Q3 estimated tax payments are due the same day. If you are a partnership or S-corp, you may owe a return and a payment in the same week.

Penalties matter more for pass-throughs. Late filing for partnerships and S-corps is charged per partner or shareholder, per month, for up to twelve months — so a five-partner firm two months late is paying ten times the headline rate. The IRS failure-to-file penalty rules set out how it accrues.

Finishing the books is not a tidiness exercise. It is the cheapest item on your list.

The five stages, and how to compress them

Businesses that fall behind tend to fall behind the same way: bank feeds connected but uncategorised, an account or two never linked at all, and a balance sheet that has quietly drifted. Work in this order and you will not redo anything.

The stages are the same either way. What changes is how much calendar you give each one.

Stage 1 — Gather, and close the gaps

Pull twelve months of statements for every bank account, credit card, loan, line of credit and merchant processor — including the accounts you forgot you had. Add payroll registers, sales-tax or GST/HST filings, and any loan amortisation schedules.

The single biggest cause of a stalled catch-up is discovering a missing account in week four. Do this first, completely, before touching a single transaction.

Seven-week runway: give it 4 days. Three-week runway: give it 2, and chase the banks the same morning you notice a gap.

Stage 2 — Reconcile cash first, everything else second

Reconcile every bank and card account month by month, oldest first. Do not chase categorisation yet.

Cash is the anchor. Until each account ties to its statement, nothing downstream is trustworthy. Park anything you cannot identify in a clearing account and keep moving — resolving one mystery deposit is not worth stalling eleven months of reconciliation.

Seven-week runway: 2 weeks. Three-week runway: 1 week, and run accounts in parallel rather than in sequence if you have more than one person on it.

Stage 3 — Categorise, then fix the balance sheet

Now code the transactions, paying particular attention to the accounts people quietly abuse: owner draws mixed with business spend, capital purchases expensed in full, credit-card payments booked as expenses.

Then review the balance sheet line by line. Undeposited funds sitting in five figures, negative liabilities, and an accounts receivable balance full of invoices that were settled in cash are the classic tells that a P&L is wrong even when it looks plausible.

Both runways: this is the stage to protect. Cutting it is how you get a return that files on time and amends in February.

Stage 4 — Reconcile the sub-ledgers

Tie accounts receivable and accounts payable to the general ledger. Confirm payroll expense and the related liabilities agree to your payroll reports.

For Canadian businesses, reconcile GST/HST collected and input tax credits to what was actually filed. For US businesses, do the same for state sales tax. Mismatches here are the ones that surface in an audit rather than in a return, which is exactly why they get skipped.

Stage 5 — Package it for your accountant

Your CPA does not want a login. They want a trial balance, comparative financial statements, bank reconciliation reports, a fixed-asset schedule, and a short memo on anything unusual.

A clean package cuts preparation fees, and more importantly it cuts the back-and-forth that consumes the final week before a deadline. If you are also sorting out fixed assets and bonus depreciation, that schedule belongs in this package too.

If you are the CPA firm

Firms feel the same crunch from the other side. Extension season is when a handful of clients arrive with nothing usable, generally in the same fortnight, and every hour a senior spends recategorising bank feeds is an hour not spent on review.

Clean-up work is well-defined and highly delegable, which is precisely what makes it worth moving off your senior bench. A dedicated team can run reconciliations and clean-up bookkeeping under your workpaper standards while your staff stay on returns and review. You keep the client relationship and the sign-off; you stop paying senior rates for data entry.

How long does a catch-up actually take?

For a single-entity business with two or three accounts and reasonable volume, twelve months of catch-up and clean-up bookkeeping is typically a one-to-two week engagement.

Multi-entity structures, retail and fuel operations with daily sales reconciliation, and anything carrying inventory run longer. The variables that stretch a timeline are almost never transaction count — they are missing statements, commingled personal spending, and prior years that were never properly closed.

Which is the argument for starting this week rather than the first week of October. Seven weeks is comfortable. Three weeks is tight but workable. Ten days is a different conversation.

Then stay caught up

The businesses that end up behind twice are the ones that treat bookkeeping as an annual event.

A monthly close — reconciled accounts, a reviewed balance sheet, financials delivered by a fixed date every month — costs less across a year than one emergency clean-up. It also means next April you file on time, because you already know the number.

If you are looking at 15 September or 15 October with books that are not ready, we can tell you in one conversation how big the job actually is and what finishing it will take. First month free, onboarding inside 24 hours, rates from $10/hour.

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This article is general information, not tax advice. Filing deadlines shift for fiscal-year filers, disaster-area relief and certain elections — confirm your dates with your CPA.