Finance & FP&A

How to build a 13-week cash flow forecast as DTC Brand Founders

Finance & FP&AFor DTC Brand Founders3 apps12 steps~24 min to set up

Your 13-week cash flow forecast lives in a Google Sheet that was last touched by whoever built it six months ago. You're manually pulling Shopify payouts, guessing at your Meta and Google ad spend timing, and copying bank transactions from three different accounts into rows nobody fully trusts. Inventory reorders — your single biggest cash outflow — are a gut call. You don't know if you have 9 weeks of runway or 14 because the sheet doesn't account for the $80K reorder you're about to place on your hero SKU. Every week you're rebuilding the same stale picture from scratch instead of making an actual decision.

Build this on Starch → See the apps used

Finance & FP&AFor DTC Brand Founders3 apps12 steps~24 min to set up

Outcome

What you'll set up

A live 13-week cash flow dashboard that pulls Plaid bank transactions and Stripe revenue automatically, so the baseline is always current without manual uploads

A side-by-side scenario model comparing your base case against a paid-ads-heavy growth push or a reorder-delay scenario, with runway and break-even shown for each

A spend anomaly alert layer that flags when any vendor — ad platform, 3PL, supplier — charges something materially different from last month, before it kills your forecast

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 Plaid bank accounts and Stripe data on a schedule — transactions, balances, payouts, and charges land in Starch automatically and refresh daily. Shopify is connected from Starch's integration catalog and the agent queries it live when your apps need order volume or payout timing data. Meta Ads and Google Ads are connected from Starch's integration catalog so the agent can pull live spend actuals for the current week when the forecast runs.

Prompts to copy

Build me a 13-week cash flow forecast using my Plaid bank accounts and Stripe revenue. Show weekly opening balance, inflows from Shopify payouts and any other Stripe charges, and outflows broken out by ad spend, inventory reorders, 3PL/fulfillment, and SaaS subscriptions. Flag any week where ending cash drops below $50,000.

Create a scenario model with three versions: base case (current burn), a scenario where I increase Meta ad spend by $30K/month starting week 4, and a scenario where I delay my next inventory reorder by 6 weeks. Show me runway and ending cash for each at weeks 4, 8, and 13.

Show me a month-over-month spend breakdown from my Plaid accounts. Flag any vendor that charged more than 20% above their 60-day average, and list every new vendor that charged my accounts in the last 30 days.

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

Walkthrough

Step-by-step

1 Connect your business checking and any credit card accounts through Plaid. Starch syncs your Plaid data on a schedule — every transaction, balance, and institution is refreshed daily without you doing anything.

2 Connect Stripe so Starch captures your Shopify payouts, subscription revenue, and any other charges. This becomes the revenue side of your forecast — actual deposits, not projected GMV.

3 Connect Shopify from Starch's integration catalog so the agent can query live order volume and payout schedules when building your weekly inflow model.

4 Connect Meta Ads and Google Ads from Starch's integration catalog. The agent queries live spend data when the forecast runs, so your ad outflows reflect what you actually spent this week, not last month's average.

5 Open the Runway Analysis app — it's a pre-built starter in the Starch App Store. Use it as your base and tell Starch to adapt it: 'Rebuild this as a 13-week rolling cash flow, with weekly rows instead of monthly, and add a line for inventory reorders as a manual input I can update each week.'

6 Add a reorder input layer. Tell Starch: 'Add a section where I can enter upcoming inventory purchase orders by SKU, amount, and expected payment date. Pull these into the weekly cash outflow rows automatically.' This is the line item your spreadsheet always got wrong.

7 Set up the Scenario Analysis app with your three most realistic planning cases: base case, an aggressive Q3 paid acquisition push, and a cash-conservation mode where you cut Meta spend 40% and delay reorders. Each scenario pulls from your actual Plaid and Stripe baseline — you only adjust the assumptions you're testing.

8 Activate Transaction Insights and configure the anomaly alert: any vendor charging more than 20% above their 60-day average triggers a flag. This catches your 3PL billing surprises, your ad account auto-spend increases, and supplier invoice errors before they corrupt the forecast.

9 Set a weekly automation: 'Every Monday at 7am, refresh the 13-week forecast, compare this week's actual opening balance to what the forecast predicted last week, and Slack me the variance with any flagged anomalies.' You start the week knowing if you're on track.

10 Before your next board update or reorder decision, open the Scenario Analysis side-by-side view and ask Starch: 'If I place a $95,000 inventory order in week 3 and Meta spend runs at $45K/month, what does my cash position look like in weeks 8 through 13?' Get the answer before you commit.

11 Review the forecast weekly, not monthly. Because Plaid and Stripe sync on a schedule, the baseline is always current. Your job is updating the forward-looking inputs — reorder dates, planned spend changes — not rebuilding the model.

12 When the forecast signals a thin week — cash below your minimum threshold — use the scenario model to decide: delay the reorder, pull back ad spend, or call your bank line. The data is in front of you; the decision is yours.

See this running on Starch

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

Try it on Starch →

Worked example

Q2 2026 reorder decision — 8 weeks out

Sample numbers from a real run

Stripe payouts (Shopify, 3-day lag)	187,000
Plaid opening balance (Week 1)	212,000
Meta Ads spend (Weeks 1–8)	-144,000
Google Ads spend (Weeks 1–8)	-38,000
Inventory reorder — hero SKU (Week 3 payment)	-95,000
3PL fulfillment fees (estimated)	-31,000
SaaS subscriptions and ops overhead	-19,000
Projected Week 8 closing cash	72,000

It's the first week of April. You're about to place a $95,000 reorder on your top SKU — the one that accounts for 60% of your revenue — because you've got 5 weeks of inventory left and lead time is 6 weeks. Before you wire the money, you open the scenario model in Starch. Base case: Stripe payouts run at roughly $23K/week, Meta and Google combined spend stays at $22.5K/week, and the reorder hits in Week 3. The forecast shows a Week 5 trough of $68,000 — tight, but above your $50K floor. Then you switch to the 'aggressive Q2 push' scenario, where you've been considering bumping Meta to $25K/week through a new creative test. That scenario drops Week 5 cash to $41,000 — below floor. You don't launch the creative test in Week 2. You push it to Week 6 when the next Stripe payout cycle catches up. Transaction Insights flagged this same week last month: your 3PL billed $4,200 more than usual on a single invoice — a counting error they corrected, but it would have made last month's forecast wrong by nearly a week of runway if you hadn't caught it. The forecast isn't a prediction; it's the earliest possible warning that a decision you're about to make has a bad week hiding in it.

Measurement

How you'll know it's working

Weeks of cash runway at current burn, updated weekly from actual Plaid balances

Inventory reorder impact on minimum weekly cash balance (the trough week)

Ad spend as a percentage of weekly Stripe inflows — CAC payback pressure shows up here first

Forecast vs actual variance on opening cash each Monday (how wrong was last week's model)

New vendor charges in the last 30 days — the most common source of forecast surprises for DTC ops

Comparison

What this replaces

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

Google Sheets (manual)

Free and infinitely flexible, but someone has to pull every number manually each week — your Shopify payouts, ad spend, and bank balance don't update themselves, and the sheet breaks the moment the person who built it leaves.

Pulse for QuickBooks / Float

Solid if your books are clean and closed within a week, but DTC founders rarely have that; ad spend and inventory costs lag in QBO, and neither tool knows your reorder schedule unless you enter it manually.

Fathom or Mosaic

Built for SaaS revenue models — MRR, churn, expansion — not for the lumpy inflow/outflow pattern of a DTC brand managing Shopify payouts, seasonal inventory, and variable ad budgets simultaneously.

Shopify Analytics + Meta Ads Manager + bank portal (open tabs)

Each platform shows you its own slice of reality; none of them talk to each other, so the cash position you actually care about exists only in the synthesis you do manually, once a week if you're lucky.

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

Does Starch connect to Shopify directly?

Yes. You connect Shopify from Starch's integration catalog and the agent queries it live when your apps run — order volume, payout schedules, and refund data are all reachable. The bank-side cash position comes from Plaid, which syncs on a schedule so your actual balances are always current.

Can I pull in my Meta and Google ad spend automatically, or do I have to enter it manually?

Both Meta Ads and Google Ads are available from Starch's integration catalog — the agent queries them live when the forecast runs. You get actual spend actuals for the week, not a manual entry you have to remember to update.

My inventory reorder amounts change every quarter. Can the forecast handle variable outflows?

Yes. When you build the app, tell Starch to add an input section where you enter upcoming purchase orders by amount and expected payment date. Those feed into the weekly outflow rows automatically. You update the reorder inputs when they change; everything else stays live.

I don't use Stripe — my Shopify payouts go straight to my bank. Does this still work?

Yes. Your Shopify payouts land in your bank account, which Plaid captures on its scheduled sync. The revenue side of the forecast comes from those deposits. If you also process through Stripe for wholesale or subscription orders, you can connect both — but Plaid alone covers the Shopify payout picture.

Is my bank transaction data stored in Starch?

Starch is not SOC 2 Type II certified today, so if your company has a compliance requirement around where financial data lives, that's worth knowing before you connect bank accounts. For most DTC founders, Starch's security posture is comparable to other SaaS tools you're already connecting to Shopify and Meta — but we'd rather you know the current state than discover it later.

Can I use this if my books aren't fully closed in QuickBooks?

That's actually where this works best. The Plaid sync pulls directly from your bank — it doesn't wait for your bookkeeper to categorize and close the month. Your cash position is current as of this morning, not as of whenever last month's reconciliation finished.

What's the difference between the Runway Analysis app and building a 13-week cash flow from scratch?

Runway Analysis is a pre-built starter in the Starch App Store — it gives you burn rate, Stripe revenue, and a forward projection out of the box. For a true 13-week cash flow with weekly rows, inventory reorder inputs, and ad spend breakouts, you'll describe what you need and Starch customizes the app for your setup. The starter is the fastest way in; your natural-language description shapes it from there.