Finance & FP&A

How to build a 13-week cash flow forecast as Small Law and Accounting Practices

Finance & FP&AFor Small Law and Accounting Practices3 apps12 steps~24 min to set up

You close your books in QuickBooks, but 'closed' means your bookkeeper finished last month — not that you know what your operating account looks like today. A four-CPA practice billing on hourly retainers has irregular cash in: one client pays in 10 days, another sits at 47. Payroll hits twice a month, malpractice insurance renews in Q2, and the line of credit has a covenant you'd prefer not to trip. Building a 13-week cash flow forecast means exporting QuickBooks transactions, opening a spreadsheet someone built three years ago, and spending a Friday afternoon reconciling why the formula is off by $4,200. It gets done quarterly, if at all.

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Finance & FP&AFor Small Law and Accounting Practices3 apps12 steps~24 min to set up
Outcome

What you'll set up

A live 13-week cash position view that pulls QuickBooks invoices, bills, and payments on a schedule and shows you week-by-week inflows, outflows, and ending cash — updated automatically, not when someone remembers to refresh the spreadsheet.
A scenario layer where you can model what happens to cash if two large retainer clients pay 30 days late, or if you bring on a lateral hire mid-quarter — side-by-side with your base case, using your actual revenue and expense data.
A spend anomaly feed that flags unexpected charges — a software subscription that doubled, a vendor you don't recognize — so nothing surprises you when you're already running lean.
The Starch recipe

Apps, data, and prompts

The combination of Starch apps, the data sources they pull from, and the prompts you use to drive them.

Apps used
Runway Analysis Scenario Analysis Transaction Insights
Data sources & config

Starch syncs your QuickBooks data on a schedule — invoices, bills, payments, vendors, and journal entries refresh automatically. Starch also syncs your Plaid-connected bank accounts on a schedule for real transaction data. The Runway Analysis and Scenario Analysis apps are pre-built starting points; you customize them with the prompts above or describe something different from scratch.

Prompts to copy
Build me a 13-week cash flow forecast using my QuickBooks invoices and bills. Show expected cash inflows by week based on invoice due dates, outflows by week based on bill due dates, and a running ending cash balance. Flag any week where ending cash drops below $60,000.
Create a scenario where two of my top-three clients by revenue pay 30 days late on their current outstanding invoices. Show how that shifts my week-by-week cash position compared to the base case, and what week I'd hit my minimum cash threshold.
Pull all transactions from my connected bank accounts for the last 60 days. Flag any vendor that charged more than 20% above their prior-period average, any new vendor I haven't seen before, and any recurring subscription I'm paying more than $500/month for.
Run these in Starch → or paste them into your favorite agent
Walkthrough

Step-by-step

1 Connect QuickBooks: Starch syncs your QuickBooks data on a schedule, pulling invoices, bills, payments, vendors, and journal entries. This takes about five minutes and requires your QuickBooks admin credentials.
2 Connect your operating bank account via Plaid: Starch syncs your Plaid-connected accounts on a schedule, giving you categorized transactions and daily balances alongside what QuickBooks shows.
3 Open the Runway Analysis starter app from the Starch App Store and tell it to reconfigure for a law or accounting practice context: 'Rebuild this as a 13-week cash flow forecast. Use QuickBooks invoice due dates as inflow timing and bill due dates as outflow timing. Show ending cash by week and flag weeks below $60,000.'
4 Review the auto-mapped categories. QuickBooks vendors will populate automatically; you may want to label a few categories specific to your practice — malpractice insurance, bar association dues, contract attorney payments — so the forecast reads in terms your partners recognize.
5 Open the Scenario Analysis app and set your base case: actual QuickBooks receivables aging, upcoming bills, and current Plaid cash balance. This becomes the anchor every scenario is measured against.
6 Build your first scenario: 'Show me what happens to cash position if the two clients with the largest outstanding invoices both pay 30 days late. Overlay this on the base case week by week.'
7 Build a second scenario for a common planning question: 'Add a lateral associate hire starting Week 6. Assume $12,500/month in additional salary and $1,800/month in benefits. How does that change my ending cash by Week 13?'
8 Open Transaction Insights and tell it: 'Flag any vendor in the last 60 days that I haven't seen in the prior 60 days, any charge more than 20% above that vendor's average, and list every recurring charge above $200/month.' This catches the malpractice insurance renewal, the unused software seat, and the court filing service that quietly increased its rate.
9 Set up a weekly automation: 'Every Monday at 7 AM, refresh my 13-week cash forecast from QuickBooks and Plaid, and send me a Slack message with ending cash for the current week, the lowest-cash week in the next 13, and any invoices more than 15 days past due.' Starch handles the scheduling — you just describe it.
10 Share the forecast view with your managing partner or office manager. Because it's pulling live from QuickBooks and Plaid on a schedule, they're always looking at the same numbers you are — no emailing spreadsheet versions.
11 Revisit the scenario layer each time something material changes: a new client engagement starts, a large receivable goes past 30 days, or you're considering a capital expenditure like a new practice management system. The base case updates automatically; you adjust the scenario assumptions and re-run.
12 Use the Transaction Insights anomaly feed as your pre-close review each month. Before your bookkeeper closes the period, scan for anything unexpected — it's faster than reviewing every line in QuickBooks and catches the things that get missed at month-end.

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Worked example

Week of April 7, 2026 — Four-CPA Practice, Q2 Planning Review

Sample numbers from a real run
Outstanding client invoices (due within 13 weeks)187,400
Retainer billings scheduled (3 clients, monthly)36,000
Payroll — Week 1 (April 11)-42,800
Payroll — Week 3 (April 25)-42,800
Malpractice insurance renewal (due April 18)-14,200
Office lease — April-8,900
Software subscriptions (annualized to weekly)-1,100
Expected ending cash — Week 13 (base case)94,600
Expected ending cash — Week 13 (two clients pay 30 days late)51,200

The four-CPA practice has $187,400 in outstanding invoices due within the 13-week window, but two of the firm's largest clients — together accounting for $68,000 of that — have an average payment lag of 41 days despite 30-day terms. In the base case, the QuickBooks invoice due dates make Week 4 look fine: ending cash of $104,000. But the scenario layer, using actual payment history rather than due dates, flags that the same two clients paying at their typical pace pushes Week 6 ending cash to $47,300 — below the $60,000 threshold the managing partner set as the minimum operating buffer. That's the week malpractice insurance renews for $14,200. The forecast doesn't change the situation, but it means the managing partner sends a follow-up on those two invoices in Week 2, not Week 6 when the calendar reminds her the insurance payment is coming. Transaction Insights separately flagged that the firm's court e-filing subscription renewed at $2,340 this quarter versus $1,780 last quarter — nobody had caught the rate increase.

Measurement

How you'll know it's working

Minimum projected ending cash over the 13-week window (vs. your operating buffer threshold)
Days Sales Outstanding (DSO) by client — how long your largest retainer clients actually take to pay vs. your stated terms
Weeks until cash drops below threshold in the base case vs. the late-payment scenario
Payroll as a percentage of projected inflows over the 13-week period
Number of invoices more than 15 days past due, by dollar value outstanding
Comparison

What this replaces

The other ways teams handle this today, and how the Starch version compares.

QuickBooks reports + Excel spreadsheet
Most practices already have QuickBooks, so this costs nothing to start — but the forecast is only as current as the last export, scenario modeling requires rebuilding formulas each time, and it lives in someone's Downloads folder rather than being shared and live.
Float (cash flow forecasting SaaS)
Float connects to QuickBooks and builds rolling cash forecasts well, but it's a separate subscription, doesn't connect your bank transaction feed for anomaly detection, and can't build the custom scenario logic or Slack automation you'd describe to Starch in plain language.
Karbon or Canopy (accounting practice management)
Both handle workflow and client management for CPA firms but neither builds a cash flow forecast or connects your bank data — they solve a different problem and you'd still need something separate for the financial visibility layer.
Hiring a fractional CFO or controller
A fractional CFO gives you judgment, not just data — useful at a certain scale — but at $2,000–$5,000/month they're updating a spreadsheet the same way your team would, just less often; the underlying data problem isn't solved.
On Starch RECOMMENDED

One platform — runway analysis, scenario planning, transaction insights all running on connected data. Setup in plain English; numbers stay current via scheduled syncs and live agent queries.

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FAQ

Frequently asked questions

We use QuickBooks but our bookkeeper is two weeks behind on categorization. Will the forecast be wrong?
Starch syncs your QuickBooks data on a schedule — it pulls what's there, including uncategorized or partially categorized transactions. The forecast will reflect whatever state QuickBooks is in. If your bookkeeper is behind, the inflow and outflow timing will be based on due dates in entered invoices and bills, which are usually current even when categorization isn't. You'll want to note the lag to your partners when sharing the view, but it's still more current than a quarterly spreadsheet exercise.
Can Starch pull from Clio or MyCase for trust account activity, not just operating accounts?
Starch connects to 3,000+ apps through its integration catalog, plus any website through browser automation. Clio and MyCase are not currently in the scheduled-sync provider list, so trust account data wouldn't sync automatically on a schedule the way QuickBooks does. If Clio or MyCase has a web interface you log into, Starch can automate through your browser to pull specific data — no API required. For operating account cash flow, QuickBooks plus your Plaid-connected bank account covers the core forecast.
Does Starch store our client financial data? We have confidentiality obligations.
Starch is not SOC 2 Type II certified today — that's worth knowing before connecting client-identifying data. The platform stores synced data from your QuickBooks and Plaid connections in Starch's database to power the live forecast. If your firm's data governance policy requires SOC 2 Type II certification from your vendors, that's an honest gap today. The roadmap includes certification, but it's not available now.
We're an S-corp and our 'payroll' includes owner draws that QuickBooks treats inconsistently. Will the forecast handle that?
You can tell Starch exactly how to treat specific accounts. When you set up the forecast, include a prompt like: 'Treat QuickBooks account [Owner Distributions] as an outflow in the week it's recorded, separate from W-2 payroll, and label it Partner Draws in the forecast view.' The agent will map it according to your instructions rather than making assumptions about your chart of accounts.
Can I share this forecast with my bank or line-of-credit lender without exporting it?
Starch apps can be shared as live views. Your bank contact would see the same numbers you see, updated on the same schedule — not a PDF snapshot from last Tuesday. If your lender prefers a static export, you can also describe an automation: 'Every Friday, generate a PDF summary of my 13-week cash forecast and email it to [lender contact].' Starch handles the scheduling and delivery.
What happens to the forecast if a client disputes an invoice and it gets written off?
When your bookkeeper records the write-off in QuickBooks, Starch picks it up on the next scheduled sync and the forecast updates automatically — that inflow disappears from the expected cash column for the week it was due. You don't need to manually adjust anything. If you want a notification when any invoice over a certain amount gets written off or marked uncollectible, you can add that: 'Alert me in Slack any time a QuickBooks invoice over $5,000 is marked as written off or bad debt.'

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