Mercury vs Brex vs Relay: Best Business Bank Account for E-commerce Sellers
For your online store—whether it's on Shopify, Etsy, or Amazon—your business bank account is key. It's where sales payouts land, how you pay for inventory, manage ad campaigns, and cover platform fees. Choosing the right bank means easier accounting, clear profit tracking, and less stress. Mercury, Brex Cash, and Relay are top fintech options for online sellers, each offering different ways to manage your money, team, and spending.
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The Quick Answer
Mercury is the default pick for most new online stores, especially solo Shopify sellers or Etsy shop owners. It's simple, has no fees, and just works for managing your main sales income. Relay is better if you're growing, have a team, or want to split money into separate buckets for things like inventory, ad spend, and taxes. Brex Cash makes sense if you're already using Brex for your corporate card to pay for large ad campaigns or supplier invoices, and you want all your spending and cash in one place.
Side-by-Side Breakdown
Mercury: No monthly fees. No minimum balance. Your money is FDIC insured up to $5 million through partner banks. They offer a Treasury product to earn interest on extra cash, which is great for saving up for a bulk inventory order. It works well with payment processors like Stripe and PayPal, and has strong API for connecting to your e-commerce tools or accounting software.
Relay: No monthly fees for the basic plan (Relay Pro is $30/month for more perks). You can open up to 20 checking accounts and get 50 debit cards per business. This is perfect for online sellers who want to keep 'Shopify Payouts', 'Amazon FBA Inventory', 'Facebook Ads Budget', 'Tax Savings', and 'Owner's Pay' in separate accounts. It also has strong team controls, letting you give specific team members or virtual assistants (VAs) access to certain budgets, like a VA managing your Google Ads account.
Brex Cash: It's free if you use their Brex corporate card. Your money is FDIC insured up to $6 million. It offers high-yield on your operating balance, which is good for holding larger sums from successful product launches or holiday sales. It's tightly connected with Brex expense management, letting you see your ad card spend and bank balance on the same screen. Note: You can't get Brex Cash on its own; it's part of the Brex card ecosystem.
When to Choose Mercury
Choose Mercury if you're launching your first Shopify store, growing an Etsy shop, or just starting out with Amazon FBA as a solo owner or LLC. You need a simple, no-fee business account that makes it easy to receive sales payouts, pay for product samples, or handle initial marketing tests. If you want a solid API to connect with your accounting software like Xero or QuickBooks, or to automate parts of your business, Mercury fits. It's also typically the fastest to open, with approvals often within 24-48 hours, letting you get your online business finances set up quickly without a trip to a bank branch.
When to Choose Relay
Choose Relay if your e-commerce business is growing, you have multiple product lines, or you sell on several platforms like Shopify and Amazon. It's ideal if you hire virtual assistants for ad management, customer service, or inventory ordering and need to give them specific budget access. Relay's multi-account setup is excellent for practicing 'Profit First' for e-commerce, allowing you to dedicate separate accounts for Cost of Goods Sold, Shipping, Marketing, Taxes, and Owner's Compensation from different sales channels. This helps you track profits accurately across your online ventures.
When to Choose Brex Cash
Choose Brex Cash if you are already using the Brex corporate card to pay for significant expenses like Facebook Ads, large Alibaba supplier invoices for inventory, or subscription software for your online store. You'll benefit from having all your cash flow and spending in one place, especially crucial for high-volume sales businesses. If you want to earn yield on cash balances from large product launches or seasonal sales without moving money to a separate investment account, Brex Cash makes this easy, integrating card spend and bank balance on a single dashboard.
The Verdict
Start with Mercury if you're a new online seller or have a small to medium-sized e-commerce operation. It's widely supported, easy to use, and has no hidden fees. Move to Relay if you find yourself needing to segment your money (e.g., 'Shopify Taxes' vs. 'Amazon Ad Spend') or if you bring on a team that needs specific payment controls. Consider Brex Cash if your business uses the Brex corporate card for most of its spending, especially for scaling ad budgets or large inventory purchases, and you want to manage everything under one roof.
How to Get Started
Mercury: Apply at mercury.com with your EIN (or Social Security Number for a sole prop), business formation documents (like LLC articles), and a personal ID. Approval is typically same-day to 48 hours, making it quick to get your online store's finances ready.
Relay: Apply at relayfi.com. Before you open, think about how you want to split your money. Plan specific account names like 'Shopify Payouts', 'Amazon Inventory', 'Facebook Ad Budget', and 'Tax Savings' upfront. This saves you time reorganizing later.
Brex Cash: Open this through the Brex onboarding process when you apply for their corporate card. Remember, you cannot open Brex Cash as a standalone checking account; it's tied to using their card for managing your e-commerce business's expenses.
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FREQUENTLY ASKED QUESTIONS
Are Mercury and Relay real banks?
No. Both are financial technology companies that partner with FDIC-insured banks to hold deposits. Your deposits are FDIC insured, but Mercury and Relay themselves are not chartered banks.
Can I use Mercury or Relay for payroll?
Yes — both support ACH transfers needed for payroll. But most businesses use a dedicated payroll platform (Gusto, Rippling, ADP) and simply connect it to their Mercury or Relay account for the ACH pull.
Which account earns the most interest on cash?
Mercury Treasury earns a competitive yield on balances over $500K. For smaller balances, Brex Cash currently offers the highest yield on operating balances among the three. Rates change frequently, so compare current rates at account opening.