Shopify Sales Are Increasing. Why Is Your Business Running Out of Cash?

A record sales month can produce a worse bank balance. The reason is timing. Shopify reports the sale the day it happens, while the business has already paid for stock, still has to pay carriers, funds advertising every day and waits for the money to settle. Revenue, contribution, accounting profit and spendable cash are four different measures, and growth can push the last one down while the first one climbs.

The scale of ecommerce growth makes the distinction more important. The U.S. Census Bureau reported $340.2 billion of seasonally adjusted ecommerce sales in the second quarter of 2026, which is 17.1% of total retail sales. Ecommerce grew 12.2% year over year, against 6.7% for total retail ¹. That is a national market result. It is not evidence that a typical Shopify store earns more profit as it grows.

The revenue screenshot does not show your obligations

Imagine a store that sells $120,000 in a month. It has orders and deposits, but it also paid its supplier weeks earlier and is already financing next month's inventory. If the supplier wants a deposit before production starts, growth requires cash before the revenue that supports it arrives.

Here is a hypothetical sequence. The amounts are cash movements, not a formal profit-and-loss statement.

Add the five fixed lines and the month nets to -$18,000 before refunds, taxes, payroll, rent or software. A store looking only at the $120,000 would call this a great month. The reorder alone absorbed 35% of the sales figure ($42,000 of $120,000) in cash. The example leaves out several real obligations and is not a projected closing balance.

Four explanations that look the same in the bank account

When cash drops while sales rise, owners usually jump to "ads are too expensive". That is one of four possible causes, and each one needs a different response.

Inventory is growing faster than it sells

Calculate stock on hand, inbound purchase orders and weeks of cover for each SKU. Weeks of cover is stock divided by average weekly units sold. If a variant sells 300 units a week and you hold 1,800, you have 6 weeks of cover. Add 900 inbound units and it becomes 9 weeks, with the extra cash already spent. A brand can post high sales while tying money up in slow variants.

The business earns contribution but collects it later

Reconcile order date, captured payment, processor payout, reserves, chargebacks and refund dates. Sales and available bank funds do not line up day by day. The gap is usually small for a steady store and large for one that has just doubled its volume, because payouts, ad bills and supplier invoices all scale on different clocks.

The order is less profitable than it looks

Allocate product cost, outbound shipping, payment fees, fulfillment, discounts and expected returns to each order. A positive gross margin can shrink sharply before advertising is counted. The break-even ROAS arithmetic shows how an order that looks fine at the revenue level can lose money once variable costs are in. If contribution per order is negative, buying more orders makes the cash problem bigger.

The business is profitable but financing its own growth

Even with healthy contribution, more inventory and slower collection can consume cash. Cutting a profitable campaign will not fix a supplier payment calendar. This is the case where the answer is working capital, payment terms or reorder timing, not the ad account.

Use a 13-week cash view, not only a monthly P&L

A short rolling forecast is more actionable than a monthly statement. For each week, show:

1. Opening cash.
2. Customer cash collections, based on payout timing rather than order date.
3. Supplier payments, split into deposits and balances.
4. Advertising charges.
5. Payroll and fixed overhead.
6. Tax obligations and expected refunds.
7. Closing cash.

Mark which amounts are committed (a signed purchase order, a scheduled payroll) and which are estimates. Then add two stress scenarios: lower sales than planned, and payouts arriving later than planned. Never count the same order twice, once as revenue and again as a payout.

If a projected week goes negative, find the earliest pressure point. The options may include changing the reorder date, prioritizing faster-turning SKUs, renegotiating payment terms or slowing acquisition that does not pay back. Each has a cost, so write the trade-off down rather than defaulting to the first idea.

A six-week example of how cash can run thin

The numbers below are hypothetical and cover only the lines shown. The store starts with $30,000, grows its weekly collections, and places a reorder in week 4 with a $42,000 deposit and a $30,000 balance in week 5.

Notice the shape. Cash rises for three weeks and looks comfortable at $56,000. The reorder then takes it to $7,200 by the end of week 5, even though collections were the highest of the period. A monthly statement for these six weeks would show strong sales and no sign of the low point.

Now stress it

Suppose collections in weeks 4 to 6 come in 15% lower than planned, because a promotion underperforms or payouts arrive later. Weeks 1 to 3 do not change. Week 4 closes at $20,200. Week 5 closes at -$2,700. Week 6 closes at $1,600. A shortfall that was invisible in the base case appears in the first week the balance goes below zero.

That is the point of the exercise. The question to answer is not "will we be profitable this quarter?" but "in which week do we run out, and what could we change before then?" Moving the balance payment by one week, ordering fewer units of a slow variant or trimming ad spend in week 5 each change the answer, and each has a cost you can weigh.

Weeks of cover and when to reorder

Stock decisions drive the largest outflow, so tie them to demand.

If you hold 1,800 units and sell 300 a week, cover is 6 weeks. With a supplier lead time of 4 weeks and a 1-week buffer, the order should be placed about one week from now. Order too early and cash sits in stock. Order too late and you sell out during your best weeks. Calculate this per SKU, not for the whole catalog, because a fast seller and a slow seller carry very different risk.

What to ask your accountant or bookkeeper

• Which of our costs are committed and which can still change?
• How are payouts and reserves from our payment processor reflected in our books?
• Are we recording inventory deposits as cash out when paid, and as stock when received?
• What is our expected refund reserve for the next 60 days?
• Which tax payments fall due in the next 13 weeks?

These questions turn a sales report into a cash plan, and the answers go straight into the 13-week view above.

Why refunds matter even when they arrive late

Promotions pull revenue forward and push returns into the following weeks. If refunds rise after a big sale, the cash gap can show up in January, not during the holiday spike. The holiday returns and January profit article shows how to put that cost back on the original orders.

Sort the problem before you change anything

Run your own cash view

The worksheet below is filled with the example above. Replace each figure with your dates and amounts. It shows the net cash movement and the weeks until the first negative balance, based only on what you enter.

Common questions

Why is my Shopify revenue up but my bank balance down?

Because revenue is recorded at the sale, while stock, shipping, advertising and payroll are paid on their own schedules. Growth usually requires paying for inventory before the sales it supports arrive.

Is a negative cash month a sign the business is unprofitable?

No. A store can have positive contribution and still run short of cash if it is funding inventory or waiting on settlement. The reverse is also possible: a profitable-looking month can hide negative unit economics.

How far ahead should a cash forecast look?

Thirteen weeks is a common working horizon because it covers one reorder cycle for most physical products and is short enough to be accurate. Update it weekly.

What is the difference between contribution and cash?

Contribution is revenue minus the variable costs of the order. Cash is what is in the account on a given day. Inventory purchases, payment timing and fixed costs sit between them.

Sources

1. U.S. Census Bureau, Quarterly Retail E-Commerce Sales, August 18, 2026 census.gov
2. Shopify, Sales and analytics field definitions help.shopify.com

Nenad Vasic

Founder and CEO of Fenix Network Media. His work focuses on the economics behind customer acquisition, conversion, measurement and profitable growth. Calculations in this article are original; third-party figures belong to their publishers and are credited in the sources.