Mercury vs Relay: Banking for a Direct-to-Consumer Brand

Cash tied up in a fresh inventory order isn't available for marketing spend or payroll, even though it sits in the same bank balance until the moment you place the order. A dedicated inventory reserve, funded ahead of each planned purchase order and drawn down when the order is placed, keeps that distinction visible. Relay's free sub-accounts make this simple to set up; Mercury's account structure supports the same approach and adds an API for a brand running inventory planning software that could pull cash position in automatically.

Most payment processors hold back a rolling reserve of a merchant's own revenue, released on a delay, as protection against chargebacks and refunds. Don't count that held-back balance as available cash in your own planning; it belongs to you eventually, but treating it as spendable today is a common way DTC brands overestimate their real liquidity. Track it as a separate line, whether inside a bank sub-account or just a running note, distinct from what's actually sitting in checking and ready to spend.

A brand that increases ad spend before confirming the unit economics on its current inventory and channel mix is financing growth against a hope rather than a number. Before scaling spend, confirm your actual contribution margin per order after all costs, product, shipping, payment processing, and platform fees, then size any marketing increase against that confirmed number rather than a blended average that might be propped up by one unusually strong week.

A brand that's just collected strong revenue and hasn't yet placed its next inventory order is holding cash that should be earning something while it waits. At today's effective federal funds rate of 3.63%¹, Mercury's automated sweep into short duration Treasury instruments turns cash sitting above your working buffer into real yield instead of a flat balance. Set the sweep threshold conservatively, above your next planned inventory purchase amount, so the sweep never ties up cash you're about to need for a purchase order.

A brand financing a large inventory order with a line of credit or a term loan is borrowing at a cost tied to the bank prime rate, currently 6.75%². Before financing a purchase order, run the actual math on whether the incremental margin from that inventory covers the financing cost with real room to spare, not just barely, since inventory that sells slower than planned while carrying debt against it compounds a cash problem rather than solving one.

A venture-backed or investor-funded DTC brand should track the same capital efficiency discipline a software company would: keep your burn multiple, net burn against net new revenue, under 2x³ as a working ceiling, even while inventory financing complicates that math compared with a pure software business. A brand burning heavily to fund inventory growth that isn't converting into a healthy, repeatable margin is spending investor capital on a problem the unit economics haven't actually solved yet.

A brand running inventory planning or 3PL software that already tracks purchase orders and stock levels gets more from Mercury's API, connecting bank data to that system directly. A smaller brand running inventory out of a spreadsheet alongside Shopify and QuickBooks is often well served by Relay's accounting integrations and extra checking accounts on the free plan (up to 20 per business per its pricing page), at least until the operation is large enough to justify dedicated inventory software.

Confirm your current inventory reserve actually covers the order you're about to place, without dipping into marketing or payroll funds. Check what your payment processor is currently holding back so you're not double-counting it as available cash. And confirm your contribution margin on the specific product line you're reordering, not a blended brand-wide average, before deciding how aggressively to scale marketing behind it once it arrives.

A brand with a strong seasonal peak, a holiday quarter that drives a large share of annual revenue, needs to plan inventory reserve and marketing scaling against that seasonal curve specifically, not against a flat monthly average that smooths away the peak entirely. Build next year's inventory reserve targets off last year's actual seasonal pattern, adjusted for growth, rather than dividing annual revenue evenly across twelve months and being caught short right before the exact stretch that matters most.

Before your next big inventory order, confirm these points:

• Your inventory reserve covers the order you are about to place, without dipping into marketing or payroll funds.
• You know what your payment processor is currently holding back, so you do not count that reserve as available cash.
• Contribution margin per order is confirmed after product, shipping, payment and other costs, before you increase ad spend.
• The incremental margin from the new inventory justifies the financing cost, if you plan to borrow against the purchase order.