For many CPA and accounting firms, the work did not “end” after April. It just changed shape. Returns moved to extension, client responsiveness dipped in summer, and by late August the same familiar pattern shows up again: a flood of K-1s, late brokerage statements, amended inputs, and rushed review cycles. The result is often a second busy season that feels less structured than the first.
Extension season does not have to be chaotic. If you treat the 9/15 and 10/15 deadlines as two separate, well-designed delivery cycles, you can turn a stressful scramble into a predictable production rhythm. The key is to shift from a “return-by-return” mindset to a sprint-based workflow, with clear gates, consistent workpapers, and defined roles across intake, prep, and review.
This article lays out a practical playbook to run extension season like a set of mini projects, and how an embedded seat model can help you scale production without losing control of quality.
Why extension season feels harder than April
April busy season is intense, but it is also structured. Everyone expects urgency, clients are primed for document requests, and teams operate in daily cadence. Extension season has different friction points:
- Inputs arrive unevenly, and often late
- Teams are tired after spring and staffing is thinner
- Review time gets diluted by meetings, PTO, and new work
- “Just one more client” decisions create creeping scope and missed cutoffs
Most firms also underestimate how much of extension work is not technical. It is administrative coordination, document chasing, organizer clean-up, reconciliation, and packaging workpapers so reviewers do not have to reconstruct the story.
That is why extension season often becomes a reviewer bottleneck rather than a preparation bottleneck.
The core idea: build two sprints, not one long grind
Instead of treating extension work as one continuous backlog from May to October, split it into two deadline-based sprints:
- Sprint A for 9/15: primarily business returns (1065, 1120S) and entities driving K-1 delivery
- Sprint B for 10/15: primarily individual returns (1040) and remaining complex items
Each sprint should have the same structure:
- Freeze scope
- Triage and intake
- Production (prep and workpapers)
- Review and resolution
- File and close out
If you run the same rhythm both times, teams build momentum and your metrics become comparable.
Sprint 0: scope freeze and return segmentation (the step most firms skip)
The most important week is the one where you decide what will be filed and what will be pushed. Scope freeze is not about being rigid. It is about protecting throughput and reviewer sanity.
Start by segmenting every extension return into one of four buckets:
Bucket 1: Ready and low risk
Inputs are complete, complexity is known, minimal open items.
Bucket 2: Ready but complex
Inputs complete, but needs senior judgment, multi-state, allocations, elections, or planning coordination.
Bucket 3: Not ready but controllable
Missing items exist, but you can realistically get them by your cutoff with clear follow-up.
Bucket 4: Not ready and uncertain
Key inputs are unknown, client responsiveness is poor, or there is open planning that will not resolve in time.
Then set two non-negotiable dates:
- A document cutoff date
- A “no-new-scope” date
When a return crosses that line, it moves to the next filing window or becomes a separate engagement, depending on your firm policy. This single discipline prevents review teams from drowning in late surprises.
Sprint A (9/15): a business-return factory that drives K-1 timeliness
A strong 9/15 sprint makes your 10/15 sprint easier. If you file entity returns earlier and deliver K-1s with fewer corrections, you reduce rework in October.
Step 1: Make K-1 dependent returns visible
Build a simple dependency map:
- Which individual returns depend on which entity K-1s
- Which entities depend on which third-party statements
- Which entities are recurring late filers
This does not need to be fancy. Even a practice management board with “blocking dependencies” works, as long as it is maintained daily.
Step 2: Standardize business-return workpapers
The fastest way to cut reviewer time is to standardize the workpaper package for 1065 and 1120S:
- Trial balance tie-out
- Book to tax adjustments schedule
- M-1/M-2 support where applicable
- State apportionment inputs and assumptions
- Owner basis and distributions schedules, if required by your process
- Open items list in one place, not in emails
When workpapers look the same across returns, managers can review for judgment, not for reconstruction.
Step 3: Create a dedicated “prep packaging” role
This role is not just a preparer. It is a person or team responsible for making each return review-ready:
- verifying inputs match the checklist
- reconciling key schedules
- confirming the open-items list is complete
- ensuring notes are written in your firm’s format
This is an ideal lane for dedicated offshore support embedded in your workflow, especially when delivered via a seat model that aligns to your tools and standards. If your firm uses an embedded team approach, this is where an Accounting Seat Model can create immediate leverage, because the goal is consistency and throughput, not one-off outsourcing.
Sprint B (10/15): a predictable cadence for individual returns
By October, the big risk is not volume. It is variability. Late brokerage statements, late K-1s, amended information, and clients who suddenly “remembered” new income streams create a churn loop.
To control it, run the 10/15 sprint with strict gates.
Gate 1: Intake completeness check
Before prep starts, confirm:
- all income documents received and categorized
- K-1s reconciled to expectation (number of entities, historical consistency)
- major deductions supported or flagged
- credits and carryovers reconciled
Anything missing goes into a structured follow-up lane, owned by one person, with templated requests and deadlines. This prevents every preparer from doing their own chasing.
Gate 2: First-pass prep with documented assumptions
Many extension returns are not complex, they are incomplete. Your first-pass prep should:
- prepare what is known
- document assumptions clearly
- list open items in a single tracker
- avoid scattered “maybe” notes
This makes review efficient, even when the final input arrives late.
Gate 3: Review resolution window
Set a fixed window for clearing review notes. If you do not control this window, you end up with endless back and forth that squeezes filing time.
A practical model is:
- Day 1 and Day 2: reviewers issue notes
- Day 3 and Day 4: preparers resolve and resubmit
- Day 5: final check and file
When the team knows the rhythm, the sprint becomes repeatable.
The metrics that keep extension season under control
You do not need dozens of KPIs. Track these three:
Cycle time by return type
Start date to file date. You want predictability more than speed.
First-pass review yield
Percent of returns that come back with minimal rework. This is a direct indicator of prep packaging quality.
Blocked work count
How many returns are stuck due to missing inputs or unresolved questions. If this number stays high, you do not have a prep problem, you have an intake and dependency problem.
How embedded Tax Seats fit into the sprint model
The reason extension season is a good fit for dedicated seats is that much of the work is structured and repeatable, especially when you have standardized workpapers and “ready for review” gates.
A dedicated offshore team member can support:
- organizer and document completeness checks
- workpaper assembly and tie-outs
- first-pass preparation under your checklist
- extension voucher packages and filing readiness
- dependency tracking and follow-ups
The advantage of a dedicated model is that the team learns your reviewers’ expectations over time, and the quality improves sprint after sprint. If you want a clearer view of that structure for US tax work, see how US Tax Seats are positioned as embedded support aligned to firm workflows.
A simple sprint calendar you can adopt this year
Here is a proven rhythm many firms follow:
Four weeks before deadline: Scope freeze and segmentation, dependency mapping, staffing plan
Three weeks before deadline: Intake gate and completeness checks, begin prep packaging
Two weeks before deadline: Production push, daily lane huddles, early review for Bucket 2 complex returns
One week before deadline: Review resolution window, filing queue, final checks
Post deadline week: Notice prevention checks, client delivery, lessons learned, checklist updates
Repeat the same cadence for both 9/15 and 10/15, with adjusted return mix.
Where to start for your firm
If you want to make extension season predictable, pick one thing to standardize and one lane to separate. The fastest combination is: define a “review-ready” checklist and create a dedicated prep-packaging lane that feeds reviewers consistently. Once you have that, you can add sprint gates, dependency tracking, and surge capacity in a way that actually reduces partner time.
Share your rough mix of extension returns (business vs individual, and the biggest source of last-minute delays) at [email protected] . I will tailor Sprint A and Sprint B lane designs to your reality, including a seat-based staffing map for extension season.
In this Article
editor
Maanoj Shah is the Co-founder & Director of Growth Strategy & Alliances at Finsmart Accounting, where he pioneered the “Accounting Seat” model—a revolutionary offshore embedded staffing solution purpose-built for Accounting and CPA firms. Widely recognized as an outsourcing and offshoring expert, Maanoj’s insights have been featured in leading accounting publications, and he regularly speaks at premier industry conferences including Scaling New Heights, Bridging the Gap, BKX, and Women Who Count.
A dynamic growth leader with over two decades of experience, Maanoj has incubated, scaled, and exited ventures across Fintech, HR, and Consulting sectors, holding various CXO roles throughout his career. His passion for scaling businesses is matched by his commitment to social impact. He is the Co-founder of Mission ICU, a national healthcare initiative that installs critical care units in underserved areas of India, and was recognized by the World Economic Forum for its last-mile impact.
Outside of work, Maanoj leads an active lifestyle as an avid tennis player and passionate golfer, blending strategy and agility on and off the court.
CONTENT DISCLAIMER
The content in this article is for general information and education purposes only and should not be construed as legal or tax advice. Finsmart Accounting does not warrant or guarantee the accuracy, completeness, adequacy, or currency of the information in the article. You should seek the advice of a competent lawyer or accountant licensed to practise in your jurisdiction for advice on your particular situation.
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