Tax return bottlenecks are the stages where returns wait longer than they are worked on. Three places to check first are waiting on client documents, waiting for a preparer to start, and waiting for review. The firm's own status data, read as days in each status, shows which one is worst, and each needs a different fix.
Which tax return bottlenecks do firms hit most?
The tax return bottlenecks firms hit most are waiting on client documents, returns that are ready but not started, and a review queue that grows faster than reviewers clear it. A fourth, waiting for client signatures, is smaller but common near deadlines. Which one dominates differs by firm and by week, so measure before choosing a fix.
A bottleneck is any stage where work arrives faster than it leaves. Returns pile up in front of it, and every stage after it sits idle or gets work in bursts. The stages themselves are covered in the post on tax season workflow stages. This post is about where returns stop between them.
Waiting on client documents. A return cannot be finished until the firm has the forms it needs. Some documents arrive late by design: the IRS General Instructions for Certain Information Returns (2025) set February 17, 2026 as the date for furnishing tax year 2025 Forms 1099-B to recipients, later than most other forms. Others arrive late because the client forgot.
Ready but not started. The file is complete, and the return sits in a preparer's queue. This often means one preparer has far more ready returns than their hours allow, while another has few.
Waiting for review. Preparers finish returns faster than reviewers can check them. Review is often one or two senior people, so it has the least spare capacity in the firm.
Waiting for signature. The return is done and the client has not signed. This is outside the firm's control but easy to forget, because nothing about it looks like work.
How to find tax return bottlenecks in your status data
Finding tax return bottlenecks in status data means measuring, for every return, how many days it spent in each status, then comparing the medians. The stage where returns sit longest, relative to the time they are actually worked on, is the bottleneck. A one-day count of returns per stage is not enough.
The method needs a tracker that records the date each return enters each status. From those dates, subtract to get days in each status per return. Then, for each status, take the median and the count of returns that went over a limit the firm sets, such as 14 days. The median shows the typical wait. The over-limit count shows how many returns are stuck.
Compare waiting stages with working stages. "In preparation" and "in review" include hands-on time. "Ready to prepare" and "waiting on client" are pure waiting. A stage where waiting time is several times the working time after it is where returns stall.
Example: days in status for a fictional firm
All figures below are fictional example values for an imaginary firm, Lakeside Example CPAs, covering tax year 2025 individual returns. They show how to read the table, not what a typical firm looks like.
| Status | Median days (example) | Returns over 14 days (example) | Bottleneck |
|---|---|---|---|
| Collecting | 9 | 18 | |
| Waiting on client | 16 | 41 | |
| Ready to prepare | 4 | 6 | |
| In preparation | 3 | 2 | |
| In review | 12 | 33 | Yes: review takes 4 times as long as preparation |
| With client for signature | 5 | 9 |
Two stages look slow. Waiting on client has the longest median, 16 days, but it sits outside the firm, and the next section deals with it. Inside the firm, review is the bottleneck: returns take a median of 3 days to prepare and then wait a median of 12 days to be reviewed. In this example, adding preparer hours would only grow the review pile.
Look at the data by week as well. A stage that is fine in February and backed up in April is a capacity problem that appears late in the season, and needs a different fix than a stage that is slow all year. The weekly work in progress report gives a week-by-week record if the firm already sends one.
Why are returns stuck waiting on clients?
Returns get stuck waiting on clients because the firm needs documents only the client can provide, and the client does not know exactly what is missing, has not received it yet, or has not got around to sending it. This delay sits outside the firm, but the firm controls how clearly and how often it asks.
How much of the total delay is outside the firm can be read straight from the days-in-status table. In the example above, the medians are 9 days collecting and 16 days waiting on the client, 25 days together, against 24 days for the medians of the four stages after that. Medians do not add up exactly, but the rough picture holds: in that fictional firm, about half of a typical return's life was spent waiting for documents.
Some of the waiting cannot be avoided. Forms have furnishing dates, and some, like the 1099-B, come later than others. For returns with wage or retirement forms there is also a firm rule: the IRS page on e-file providers and Forms W-2, W-2G and 1099-R says authorized e-file providers are prohibited from submitting electronic returns before receiving all of those forms, except when a substitute Form 4852 has been completed because the taxpayer cannot get a correct form.
Much of the waiting can be shortened. The common causes are within reach:
- A vague request. "Please send your tax documents" does not tell the client that the second brokerage account's 1099 is missing.
- No follow-up rhythm. One request in January and silence until April leaves the client to remember.
- Documents sent in pieces. A client who sends files through email, phone photos and a portal download in three batches makes it hard for anyone to see what is still out.
Chasing outstanding documents is a topic of its own, with request wording, reminder timing and escalation. The missing documents category covers it.
The first cause is where software helps most. Schema CPA puts every client's uploads in one file, checks them against last year's documents, and drafts a reminder that names what is still missing; the firm reviews the draft and sends it. The document types section of the homepage lists what it reads.
Fixing a review bottleneck versus a preparation bottleneck
A review bottleneck and a preparation bottleneck need opposite fixes. A preparation bottleneck means complete files wait for a preparer, so the fix is spreading ready returns across preparers or adding preparation hours. A review bottleneck means prepared returns wait for a reviewer, so the fix is adding review capacity or sending cleaner returns to review.
Fixing a preparation bottleneck
A preparation bottleneck shows up as a high median in "ready to prepare". Check whether it is spread evenly or concentrated on one person. If one preparer has most of the ready returns, the fix is reassignment: move unstarted returns to preparers with capacity. If every preparer has a long queue, the firm is short of preparation hours, and the options are adding hours, extending some returns early, or taking on fewer clients next year.
Fixing a review bottleneck
A review bottleneck shows up as a high median in "in review", often with a pile of returns that arrived in the same week. Three fixes help:
- Add a reviewer for the peak weeks. A second senior person reviewing simpler returns in late March and April takes pressure off the main reviewer.
- Order the queue. Review returns by due date and complexity, not by arrival. The post on how to order a review queue for tax preparers covers the ordering rules, so this section only names the need.
- Send cleaner returns. Returns that come back for missing documents or simple errors take review time twice. A preparer checklist before handoff cuts the second pass.
Review queues by preparer are part of Schema CPA's Practice plan, alongside its document checks.
Why review stays with people at all, even as other steps are automated, is covered in how to automate tax season, which also lists the stages software can take on.
Bottleneck fixes that just move the queue
Some bottleneck fixes just move the queue to the next stage instead of shortening the whole process. Adding preparers in front of a review bottleneck, pushing clients to send documents faster when preparation is already full, or rushing review to clear a pile all shift the waiting somewhere else. The total days from request to filing stay the same.
The test for any fix is the total, not the stage. If the median days from first request to filed return does not fall, the fix moved the pile. Check the stage after the one you fixed: if its median rose by about as much as the fixed stage fell, the queue moved.
Common examples:
- More preparers, same reviewers. Preparation speeds up, and review, already the bottleneck, gets longer.
- Faster document collection, no preparation capacity. Files become complete sooner and then wait in "ready to prepare" instead of "waiting on client". This is still a gain if it moves the waiting inside the firm, where it can be scheduled, but it is not a shorter season.
- Rushed review. Clearing the review pile by reviewing faster sends errors to the signature stage or, worse, to filing. Returns that come back after filing cost more than any queue.
- Early extensions without a schedule. Extending returns clears April, and the same returns pile up in September and October unless they are scheduled across the months in between.
The fix that shortens the total is the one applied to the true bottleneck, the stage with the longest wait relative to its working time. In the example table, that is review. Fix it, measure again, and the next-slowest stage becomes the new bottleneck. That is expected. A firm that keeps measuring days in status each week will always have a bottleneck; the goal is that each one is shorter than the last.