Finance & FP&A

How to build a 13-week cash flow forecast as Professional Services Founders

Finance & FP&AFor Professional Services Founders3 apps12 steps~24 min to set up

Your 13-week cash flow forecast lives in a Google Sheet that gets updated whenever you remember to update it — which means it's usually two weeks stale when a client asks for a status on invoice timing or your accountant wants to know if you can hire a mid-level consultant. You're pulling Stripe invoices manually, estimating payroll from memory, and guessing at retainer renewal dates from a HubSpot pipeline that only reflects deals you bothered to log. A bad month hits you sideways because nothing flagged the warning three weeks earlier. Enterprise PSA tools would solve maybe 20% of this at 10x the cost and a three-month implementation. So the spreadsheet stays.

Build this on Starch → See the apps used

Finance & FP&AFor Professional Services Founders3 apps12 steps~24 min to set up

Outcome

What you'll set up

A live 13-week cash inflow forecast built from actual Stripe invoice schedules and HubSpot deal close dates, updated automatically — not the version you last touched on a Tuesday

A real-time burn rate dashboard that pulls every payroll run and vendor payment from your Plaid bank feed, so you know your true weekly cash out before it clears

A scenario layer that shows you what happens to runway if a retainer doesn't renew, you hire that senior consultant, or a key client pays 30 days late

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 Stripe data on a schedule (invoices, charges, payouts, subscriptions) and your Plaid bank feed on a schedule (transactions, balances, categorized spend). HubSpot deals are connected from Starch's integration catalog and queried live when the forecast needs pipeline-weighted inflow projections. Paylocity or ADP payroll data syncs on a schedule if you use either; otherwise Starch automates payroll data extraction through your browser — no API needed. No spreadsheet uploads, no manual pulls.

Prompts to copy

Build me a 13-week cash flow forecast that pulls scheduled invoice payments from Stripe, flags any invoice more than 14 days past due, and shows my net cash position week by week

Show me a scenario where my largest retainer client (currently $28k/month) doesn't renew in week 6 — what does that do to my 13-week runway and when do I hit a cash floor?

Pull all outgoing transactions from my Plaid accounts for the last 90 days, group them by vendor category (payroll, software subscriptions, contractors, travel), and flag anything that increased more than 20% month over month

Run these in Starch → or paste them into your favorite agent

Walkthrough

Step-by-step

1 Connect Stripe as a scheduled-sync provider — Starch pulls your invoices, subscription schedules, and payout history automatically. This becomes the backbone of your inflow forecast: every outstanding invoice has an expected settlement date.

2 Connect Plaid to your primary operating account and any secondary accounts. Starch syncs transactions and balances on a schedule, giving you a categorized record of every dollar going out — payroll, SaaS subscriptions, contractor payments, travel.

3 Connect HubSpot from Starch's integration catalog. The agent queries your deals live to pull pipeline-weighted close dates and deal values, so expected client payments from proposals-in-progress show up as probability-weighted inflows in weeks 8–13.

4 Start with the Runway Analysis app. It immediately shows you net burn against current cash using your Plaid and Stripe data. Customize the prompt: 'Break down my weekly cash outflows into payroll, contractor fees, software, and G&A — show 13 weeks forward with actuals for the last 4.'

5 Build your inflow waterfall: tell Starch which Stripe invoices are on net-30 terms, which retainers auto-collect, and which require manual follow-up. Starch generates a week-by-week inflow schedule based on invoice due dates plus your historical collection lag.

6 Layer in your HubSpot pipeline for weeks 8–13. Prompt Starch: 'Pull all HubSpot deals in Proposal Sent or Contract Out stage, apply a 60% close probability, and add their expected first invoice date to my week 9–13 inflow projection.'

7 Open the Transaction Insights app to identify fixed versus variable cash outflows. Flag your top 10 recurring vendors by monthly spend — this becomes your baseline cash-out schedule. Starch flags any new vendor charges or unusual spikes automatically.

8 Use Scenario Analysis to model your two biggest risks. For a professional services firm, these are usually: a major retainer not renewing, or a hire adding $15–20k/month in fully-loaded cost before the revenue catches up. Run both. See the cash floor date.

9 Set up a weekly automation: 'Every Monday at 8am, refresh my 13-week cash flow forecast, flag any invoice that moved past due since last week, and Slack me a summary of net inflow vs. outflow for the coming week.' Starch builds this against your live data.

10 Add a collections alert: 'If any Stripe invoice is more than 21 days past its due date and over $5,000, draft a follow-up email from Gmail and flag it in my weekly summary.' This replaces the Friday afternoon AR chase.

11 Share a read-only forecast view with your accountant or CFO-for-hire. They see the same live numbers you do — no more emailing exports, no version control problems, no 'which sheet is current.'

12 Review actuals versus forecast at the end of each 4-week block. Prompt Starch: 'Compare my forecasted inflows for weeks 1–4 against what actually landed in Plaid. Show me the variance by client and explain what drove it.' Use this to tighten your collection-lag assumptions.

See this running on Starch

Connect your tools, describe what you want, and the agent builds it. Closed beta is free.

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Worked example

Week of April 14, 2026 — 13-Week Forecast Snapshot

Sample numbers from a real run

Retainer — Client A (auto-collect via Stripe)	28,000
Project invoice — Client B (net-30, due Apr 22)	14,500
Project invoice — Client C (net-30, due Apr 28, 11 days overdue)	9,200
HubSpot pipeline — Client D proposal (65% probability, expected close wk 7)	19,500
Payroll run — April 15 (Paylocity, synced)	-38,400
Contractor fees — 3 specialists (Plaid, last 4 weeks avg)	-12,200
SaaS subscriptions (Plaid, recurring)	-3,100
Opening cash balance (Plaid, April 14)	187,000

On April 14, Starch shows $187,000 in the operating account. Week 1 inflows are reliable: Client A's $28,000 retainer auto-collects via Stripe on the 15th. Client B's $14,500 invoice is due April 22 — historically they pay in 28 days, so Starch projects it landing in week 2. Client C's $9,200 is flagged: it's 11 days past due, which Starch caught automatically and added to the follow-up queue. Cash out this week is $38,400 in payroll plus $3,100 in SaaS. Net week 1: roughly -$1,900 before Client B lands. By week 6, the Scenario Analysis layer shows a problem: if Client D's proposal doesn't close and Client C's retainer renewal (due week 7, $9,200/month) stalls, the 13-week cash floor drops to $61,000 — uncomfortable for a firm that carries $40,000 in average monthly payroll. That's the conversation you have with your operations lead in April, not in June when it's obvious.

Measurement

How you'll know it's working

Days Sales Outstanding (DSO) by client — how long between invoice sent and cash received, tracked weekly against your net-30 terms

Utilization-adjusted burn rate — weekly cash out per billable head, so you know whether a slow month is a capacity problem or a collections problem

Retainer renewal coverage ratio — percentage of next 13 weeks' projected inflows that are confirmed retainers vs. pipeline-dependent

Cash floor date — the week at which operating cash hits your minimum comfortable balance, given current burn and projected inflows

Proposal-to-cash lag — average weeks from HubSpot deal close to first Stripe payment landing, used to calibrate pipeline-weighted inflow forecasts

Comparison

What this replaces

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

Google Sheets (manual)

Free and fully flexible, but the forecast is only as good as the last time you updated it — which means it's usually stale when you need it most, and there's no automatic flagging of overdue invoices or cash floor warnings.

Kantata / Projector / Deltek

Purpose-built for professional services cash management, but priced for firms with 100+ seats, require a multi-month implementation, and still don't connect your bank feed natively — you're paying enterprise prices for a spreadsheet replacement.

Float (cash flow forecasting)

Solid purpose-built cash flow tool with QuickBooks/Xero integration, but it doesn't know your HubSpot pipeline, can't run natural-language scenarios, and adds another subscription your team has to maintain separately from your other tools.

QuickBooks + accountant monthly close

Accurate historical picture, but you're looking at last month's numbers, not next 13 weeks — and your accountant's close cycle means you're always making decisions with a 3–6 week lag on actuals.

Harvest + Float + HubSpot (manual stitching)

The typical professional services founder stack — each tool does its job, but the connections between them are manual exports and copy-paste, and the 13-week view never actually exists in one place at one time.

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.

Try it on Starch →

FAQ

Frequently asked questions

My Stripe invoices are a mix of auto-collect retainers and manually-sent project invoices. Can Starch tell the difference?

Yes. Starch syncs your full Stripe invoice and subscription data on a schedule, so it sees which invoices are attached to active subscriptions (auto-collect) and which are one-off charges. You can prompt Starch to separate them in the forecast: 'Show retainer inflows and project invoice inflows as separate line items, and flag any project invoice that's past its due date.' The auto-collect retainers land as confirmed inflows; project invoices get your historical collection-lag assumption applied.

I use QuickBooks for bookkeeping. Can I pull that into the forecast instead of or alongside Plaid?

Yes — Starch connects directly to QuickBooks and syncs invoices, bills, payments, and vendors on a schedule. One honest caveat: the report views (P&L, Transaction List) are temporarily disabled pending a connector fix, but entity-level data — which is what the 13-week forecast needs — syncs normally. You can use QuickBooks for your accounts payable picture and Plaid for your actual bank balance, or either one on its own depending on how your books are structured.

My pipeline is in a Google Sheet, not HubSpot. Can I still get pipeline-weighted inflows in weeks 8–13?

Yes. Connect Google Sheets from Starch's integration catalog and the agent queries it live. Tell Starch: 'Pull the deal name, expected close date, contract value, and probability columns from my pipeline sheet, and add probability-weighted first invoice dates to my 13-week inflow forecast.' It's not as structured as a CRM pull, but if your sheet has those columns, it works.

Is Starch SOC 2 certified? I have a client contract that asks about this.

Not yet. Starch is not currently SOC 2 Type II certified. If your client contract requires your tools to carry SOC 2 certification, that's worth knowing upfront. It's on the roadmap; it's just not there today.

Can I give my accountant or fractional CFO access to the forecast without giving them access to everything?

You can share the forecast view with them directly through Starch. They see the live numbers without needing to touch your underlying connections or other apps. This replaces the weekly 'here's the updated sheet' email and means they're always looking at the same data you are.

What happens if a client pays early or late? Does the forecast update automatically?

Yes, for anything that touches your bank feed or Stripe. When a payment lands in your Plaid account, the actual cash position updates. When a Stripe invoice is paid, it moves from projected to confirmed. The forecast compares actuals to projections automatically. You can also prompt Starch: 'Flag any week where actual inflows came in more than 15% below forecast and tell me which invoice caused the gap.'

I have contractors paid via ACH on irregular schedules. How does Starch handle variable cash outflows?

Plaid captures every ACH debit from your operating account, categorized by vendor. Starch can look at your last 12 weeks of contractor payments and build an average weekly cash-out estimate, or you can tell it which contractors are on predictable schedules and which are project-based. Prompt: 'Separate my contractor cash outflows into recurring (same vendor, monthly pattern) and variable (project-based), and show each category as a separate line in my weekly cash-out forecast.' The irregular ones get flagged as a range rather than a point estimate.