Relay vs Mercury for Accounting Firm Workflows

You're closing the books for a dozen clients, and no two of them bank the same way. One shares the owner's login over email. One gave you view-only access. One has a bank feed that broke weeks ago and nobody caught it.

Each of those clients picked the bank themselves. You're the one running all of them, and that changes what a banking platform has to do: give everyone on your team the right access to each account, keep the books in sync, and hold the monthly close steady as the client list grows.

Choosing a banking system for the whole roster means standardizing on one system that runs the prepare → review → approve → pay workflow the same way for every client. Relay and Mercury are the two platforms firms weigh for it, and they're built for different users. For accounting firms managing multiple client entities, Relay is the stronger operational fit: role-based logins on every account, up to 20 checking accounts per business for Profit First-style allocations, and two-way QuickBooks Online and Xero sync. Mercury is the better choice for a venture-backed startup that needs treasury and a higher-yield cash sweep on its own balance sheet.

And increasingly, the accountant is the one making the call. A 2025 Intuit QuickBooks survey of 700 accounting professionals found nearly 8 in 10 expect their strategic advisory work to grow over the next year. When you advise the client on which tools to use, the one that fits your workflow across the book is the one that compounds.

Relay vs Mercury for accounting firms: the quick verdict

Standardize on the platform that fits a repeatable, multi-client workflow. For most firms, that's Relay. For a treasury-heavy startup managing its own runway, it's Mercury.

Mercury’s published materials do not state an account limit, and its QuickBooks Online and Xero integrations are one-way transaction feeds per Mercury’s documentation.

The rows that decide a firm’s choice aren’t price or yield. They’re role separation, account structure, and how cleanly the books stay in sync when someone other than the owner is doing the work.

How does each platform handle role-based access across multiple client entities?

Relay gives every accountant and bookkeeper their own login with exactly the access they need, on every plan. No shared passwords, no logging in as the client, no all-or-nothing admin rights. When you manage banking for a dozen clients, role separation keeps the audit trail clean: the owner approves, the bookkeeper prepares, and each action is attributable to a person.

Mercury offers four permission levels: Admin, Employee, Accountant, and Custom. That works for one company with one finance team.

It strains when you’re the external accountant moving between client accounts. The model is built around a single business granting access to its own staff, not a firm operating across a roster of separate entities. View-only is often too little to do the work, and Admin is more than a client wants to hand out.

The practical test is what happens at month-end across ten clients. With role-based logins on each account, your team works inside every client’s banking with the right permissions and a record of who did what. The same workflow scales across the whole book instead of getting rebuilt client by client.

Which platform better supports Profit First and multi-account cash allocation?

Relay was built for the account structure Profit First depends on. You can open up to 20 checking accounts per business on Starter and Grow, and up to 50 on Scale, then set percentage- or dollar-based auto-transfers that fire every time a deposit lands. Revenue comes in, and a set share moves to profit, tax, owner’s pay, and operating expenses automatically. Those allocation rules are included on every plan, with no upgrade required.

Mercury uses one primary checking account with sub-accounts underneath. You can separate the money, but you move it between sub-accounts manually rather than on deposit-triggered percentage rules, and Mercury’s materials don’t document an automated allocation engine. For a firm running Profit First or any purpose-based cash structure across clients, the structure becomes something you maintain by hand instead of something the platform enforces on every deposit.

For accountants who design the cash flow system and then hand it back to the client to run, automation is the whole point. A rule that executes on every deposit holds the discipline in place even when you’re not looking.

How do Relay and Mercury compare on QuickBooks Online and Xero sync?

Relay runs a two-way sync with QuickBooks Online and Xero on every plan. With QuickBooks Online, transactions, bills, invoices, and payments move both directions; with Xero, transactions and payments sync two ways. Bills and payments carry their detail through, which means reconciliation isn’t a manual re-entry job and the bank feed doesn’t quietly break mid-month.

Mercury’s QuickBooks Online and Xero integrations are one-way transaction feeds, per Mercury’s own documentation. Mercury sends a daily bank feed with merchant detail and AI-suggested categories you review and approve, but changes in the books don’t sync back to Mercury. For a single startup with a light transaction load, a clean one-way feed is enough. For a firm closing books across many clients, two-way sync is what keeps the ledger and the bank account from drifting apart.

Reconciliation eats the hours. Every broken feed, every transaction that didn’t carry its memo or line items, every payment you re-key becomes overhead multiplied by your client count. The sync model decides whether a close takes an afternoon or a week.

How does bill pay and the approval workflow compare for client AP?

Relay Bill Pay runs the full prepare → review → approve → pay loop inside the same account the client banks in. You upload or email bills, code them, and route them through multi-step approval rules so the right person signs off before cash leaves. Batch payments handle many vendors at once. Core bill pay is on every plan; approval workflows and batch payments step up on Grow and Scale. Because banking and bill pay live in one place, there’s no second tool, no second login, and no separate reconciliation step for the AP you manage on a client’s behalf.

Mercury supports bill pay with approval workflows for purchases, which covers a single company managing its own vendors. But its AP lives inside one business’s account, and a firm needs to run the same accountable workflow across many client accounts without bolting on a separate tool for each one.

When you delegate AP, role separation and approval rules keep the owner in the loop on what goes out without forcing them to touch every payment, and they give you a workflow you can apply identically from one client to the next.

Which platform should your firm standardize on?

Mercury wins for venture-backed startups sitting on a large cash balance. Mercury Treasury sweeps idle cash into money market or ultra-short bond funds yielding roughly 3.00% to 3.61% depending on balance. For a company managing its own runway, that’s a real advantage.

Two caveats decide whether it applies to you: Treasury requires a $250,000 minimum across all Mercury accounts, and it’s SIPC-protected as an investment product, not FDIC-insured like a deposit. It also excludes sole-proprietor LLCs and nonprofits. For a funded startup with seven figures of idle cash, that’s a strong reason to bank with Mercury. For most of a firm’s small business clients, it’s not in play.

Relay wins for the firm itself. The decision isn’t which platform has the better single account. It’s which one fits the way you actually work: role-based access on every client entity, an account structure that enforces cash allocation automatically, two-way accounting sync that holds the books together, and an AP workflow you can run identically across the roster. Standardizing on one platform that does all four means you train your team once, set up each new client the same way, and stop reassembling the workflow per engagement.

A startup picks its bank for one balance sheet. A firm picks for repeatability across every account it touches. They’re not the same problem, and they don’t have the same answer.

How to set up Relay for a multi-client accounting workflow

Start by adding your firm’s team members to each client account with role-based logins scoped to what they do: preparers get bill creation and coding, approvers get sign-off, and the owner keeps final approval. The same role map applies to every client, so a new engagement is a setup you’ve already run.

Next, build the account structure. Open separate checking accounts for the client’s operating cash, taxes, profit, and owner’s pay, then set percentage-based auto-transfers so each deposit splits automatically on the schedule you designed. Connect QuickBooks Online or Xero for two-way sync so transactions, bills, and payments stay current in the ledger without manual entry. Then move AP into Relay Bill Pay and set the approval rules that match how that client wants payments authorized.

Run that same sequence on every client and the firm gets one repeatable system instead of a different setup per account. That’s why when you open a Relay account, you build that repeatability: role-based access on every client entity, a multi-account structure for Profit First-style allocations, two-way QuickBooks Online and Xero sync, and a Bill Pay approval workflow for client AP, all with no monthly maintenance fees on the Starter plan.

Frequently asked questions

Is Relay or Mercury better for accountants and bookkeepers?

Relay is the better fit for accountants and bookkeepers managing multiple client entities, because it offers role-based logins on every account, automated cash allocation, and two-way QuickBooks Online and Xero sync. Mercury is better suited to a single venture-backed startup managing its own treasury and runway.

Does Mercury support Profit First?

Mercury offers one primary checking account with sub-accounts, so you can separate your money, but you move it between them manually rather than through deposit-triggered percentage rules. Relay is built for Profit First’s account structure, with up to 20 checking accounts per business and percentage-based auto-transfers that allocate every deposit automatically on all plans.

Does Relay sync two ways with QuickBooks Online and Xero?

Yes. Relay syncs two ways with QuickBooks Online for transactions, bills, invoices, and payments, and two ways with Xero for transactions and payments, on every plan. Mercury’s QuickBooks Online and Xero integrations are one-way transaction feeds, so changes in your books don’t sync back to Mercury.

Can my whole firm get separate logins to a client’s Relay account?

Yes. Relay provides role-based logins on all plans, so each team member gets exactly the access they need with no shared passwords. You can scope preparers, approvers, and view-only roles separately on every client account, which keeps the audit trail clean across the roster.

How many bank accounts can a business open with Relay?

A business can open up to 20 checking accounts on the Starter and Grow plans, and up to 50 on Scale, plus up to two savings accounts. Separate accounts for each purpose make Profit First and other cash allocation methods practical to run for every client.