Relay vs Brex

Relay operates like a traditional bank. Once you hand out your routing and account numbers, vendors can pull ACH payments just like they would with any other bank. This is risky because once someone has your routing and account numbers, they have the bare minimum they need to try pulling money out of your account without you pushing “send” on anything.

That’s why “just handing out” your routing and account numbers is more risky than sharing a unique payment link and why most businesses tend to prefer stronger controls.

With that, Relay’s FDIC coverage goes up to $3 million dollars. Relay spreads your money across several FDIC-insured banks automatically so that more of your balance stays insured instead of being stuck at the $250k limit of a single bank.

Relay does not have a treasury account.

Instead, it offers a savings account where you can earn interest on your balance. With that, the interest rate varies and depends on the subscription plan you pay for. So if you're on the free plan of Relay, expect to get a lower interest rate.

While this is simple, the reality is you are not investing in government securities, treasury funds, or multi-pool yield strategies and it means you miss out on the higher yields.

In summary, if you have a large amount of money in your account (e.g. $250K+) you should automatically consider switching to Mercury since you will make more money on your money.

When you forward a bill to Relay's unique Bills Inbox email, it automatically extracts key details like vendor name, invoice number, amount, and due date using built-in document recognition so that you don't need to manually enter in the details. You can then review and edit the bill before paying.

The thing is, Relay doesn’t have vendor onboarding, which means it doesn’t automatically collect W-9s. This puts more admin on your plate before tax time. It’s a small thing that makes a huge difference if you work with a lot of contractors. You’ll need to email everyone separately, and it’s just a pain.

Similar to other banks, with Relay you can create a check payment and they will print it off and mail it on your behalf.

That said, you cannot send a physical attachment (e.g. PDF or form) with the check. You can upload it to their system and include a memo line, but if you need to send a physical document to the government for example, you'd need to figure out a solution outside of Relay.

Domestic and International wires to a USD account are free.

Relay includes invoicing and payment links so you can create, send, and track invoices without needing a separate tool.

Relay lets you open up to 20 checking accounts per business, which you can nickname for things like Income, Profit, Owner’s Pay, Taxes, and Operating Expenses, plus up to 2 savings accounts that currently earn around 1–3% interest on idle cash.

Relay is built around "Profit First" banking, that is one of their core marketing messages.

You can create percentage‑based auto‑transfer rules (e.g. Say you set a target of $1K in your income account, and twice a month, anything above that is distributed by percentage to Payroll, Tax, Owners Comp, etc.). So say your balance hits $5k, the $4k will be distributed accordingly to your percentage rules.

As a heads up though, these rules only apply between Relay checking accounts (not to savings accounts) where as with Mercury for example, you can set up similar rules that also work between savings and Treasury accounts.

If you run multiple businesses, Relay lets you register several entities under a single login and then toggle between them from a dropdown, with each business having its own set of accounts, cards, and permissions.

That said, Relay does not offer any Personal Banking solutions so you'd still need a totally separate bank for that (we are obsessed with Mercury Personal Banking, which is why we use Mercury for both business + personal, but hey, even if you use Relay for business we'd recommend switching to Mercury for personal use since its that good).

Relay gives you team access controls with several permission levels like Administrator, Manager, Cardholder, Deposit‑only, Approver, and Read‑only, and you can restrict people to specific checking/savings accounts so, for example, your marketing manager only sees the Marketing account and not Payroll.

Relay supports bill approval workflows inside its bill pay module: you can set rules like “bills over 1,000 dollars require approval” and route them to one or more approvers before they can be paid, which is great for small teams wanting oversight on vendor payments.

As a heads up though, these approval rules are tied to only bills in Relay (not any payment over X amount via ACH, wire, internal transfers, etc must be approved).

Relay has an easy to use interface, especially when it comes to setting up the auto-transfers between accounts for Profit-First banking. The app is clutter free and the dashboards are simple, intuitive, and uncluttered.

With Brex Vault, deposits can receive up to $6M in FDIC insurance through it's network of partner banks, and you can set basic controls around incoming ACH debits to reduce the risk of unauthorized transfers.

That said, the overall setup of it all feels more like it was tacked on to check a box, that is banking, versus them actually trying to innovate and set a new standard in the space.

The biggest concern right now is that there's quite a bit of long-term uncertainty here around Brex because they were acquired by Capital One, which could eventually lead to the product being folded into Capital One's more outdated banking stack. In-fact, many startup founders and business owners we know have moved off Brex since this announcement.

So while Brex is technically safe and secure as a platform, it doesn't feel quite as focused or purpose-built around the core banking experience as Mercury, and there's a lot of uncertainty around it right now especially.

Brex lets you earn some yield on idle cash, but the setup is fairly basic. Funds are placed into a government money market fund (DGVXX), and you can move money between checking and treasury without too much friction.

The main downside is that Brex essentially gives you one default fund rather than a broader treasury options like Mercury allows for. Which also makes sense, because unlike Mercury, Brex is less of a banking solution, so this it more bolted on functionality just to check the box in this area, versus innovating on the experience.

Brex can move money, but the whole experience feels like banking was added as an afterthought.

Yes, you can send and receive ACH, wires, and checks. You can onboard vendors through a secure link, collect W-9s, upload invoices into bill pay, and add approval flows. So on paper, there's a decent amount of functionality.

The problem is that once you actually start using it, the whole thing feels bolted on. To us, it feels much more like an expense management platform that added banking later, rather than a banking product that was built from the ground up to make transferring funds seamless. Even the way Brex frames it as a "cash management account" instead of a bank account kinda gives that away.

While Brex has native invoices, payment links, ACH/wire payments, and even ACH direct debit, it just feels unpolished an unintuitive. Compared to Mercury, it just feels old.

Not to mention, if you're using one of the newer AI accounting tools, the limitations become even more obvious. For us, that was a complete deal breaker. We use Kick, and it integrates directly with Ramp (virtual cards) and Mercury (banking), but not Brex. So unless you're cool with not exploring the world of AI accounting tools, I'd say you're better off skipping Brex.

Brex is more focused on finance‑team‑heavy companies rather than small teams.

Brex actually goes very far on the "many accounts" front: if you're approved for a Brex business account (you need a $50k bank minimum, or $1 million in revenue), you can create up to 240 separate checking accounts under one EIN, each with its own account and routing number so you can separate cash for things like payables, receivables, payroll, and tax.

But you don't get a card for each account like you would with a bank. Since Brex is an expense management software, you just spend on cards and they are all tied to one "entity" where payments come from.

Admins can set "auto‑transfer rules" per checking account, like "always keep this account at $100K" but you are unable to set auto-transfer rules like "every time money lands, automatically slice 30% tax, 20% for payroll, etc to different buckets."

All of your Brex business accounts banking (checking, treasury, vault) are tied to a single primary legal entity, and deposits must be in that primary entity's name.

If you want a completely separate Brex business account for another legal entity, you have to apply again and run it as a separate account, rather than just adding another full banking "workspace" under one login the way Mercury and Ramp allow for multiple entities.

There is no Brex personal banking solution so you can't manage your personal finances under one login (we are obsessed with Mercury Personal Banking, which is why we use Mercury for both business + personal).

Brex is very strong on roles and permissions: you get Account admins (full banking + payments), Card admins, Finance admins, plus more limited roles like Employee, Reimbursement‑only, and Auditor, and on top of that you can create granular custom roles that decide exactly who can "manage accounts & payments" versus just view data.

For each Brex checking account, you can toggle on payment approvals, set a minimum amount that requires approval, and choose one or more users who must approve any outbound payment or transfer above that threshold.

There's a lot of functionality, but it still feels more pieced together than purpose-built.

Brex's interface is fine, but the banking UX just doesn't feel like the main product.

It's relatively modern, and you can usually get to what you need without fighting with it, but once you're actually trying to do banking things, it feels like you're navigating a platform that was built for spend/expense management first, with banking being added in as an afterthought.

The biggest friction is that your cash experience is split across checking, treasury, and vault, so even simple questions like "where's our money?" can require some digging. And while search generally helps, it doesn't fix the constant underlying feeling that the banking interface is more of a secondary layer.

All-in-all, it just doesn't feel like a bank that obsessed over making money movement and visibility of your cash super easy, unlike dedicated banking apps like Mercury.