If you want to separate tax money, payroll, and operating cash without opening a stack of legal bank accounts, a handful of business banking platforms built exactly that. It's called a sub-account, sometimes a reserve or an envelope, and it lives inside one main account.
Novo, Bluevine, Relay, and Baselane all offer some version of it. Mercury takes a different approach entirely.
We verified every limit, fee, and account structure below directly against each provider's own site on September 28, 2026. Here's what actually differs between them, and what “sub-account” means depending on which bank you're asking.
What is a sub-account, actually?
A sub-account is a sub-division of cash inside your business checking account, built for budgeting rather than for legal separation.
You move money into buckets labeled “taxes” or “payroll” or “Q4 marketing.” The bank's dashboard tracks the balance in each one separately from your main spending balance.
The money never leaves your bank. It's not a new legal account with its own tax ID or ownership structure.
It's an accounting layer the bank built on top of one account, so you can see at a glance how much cash is actually free to spend versus how much is already earmarked.
This is the same idea behind “envelope budgeting,” a personal-finance method that predates business banking by decades. Novo, Bluevine, Relay, and Baselane essentially digitized the envelope system and attached it to a business checking account.
Mercury doesn't build this. Its guidance, published on its own blog, is to open additional full checking accounts instead, up to 100 of them, and use each one as its own envelope.
Sub-account vs. multiple checking accounts: what's actually different
Here's the distinction that actually matters, and it's mostly about account numbers.
A true sub-account, like Novo's Reserves, shares the parent account's single routing and account number. It's not a separately addressable account.
Money inside it is still, from the bank's and the IRS's perspective, sitting in one account with internal labels on top.
Opening multiple full checking accounts, which is Relay's and Mercury's model, gives you a separate account number for each one. Mercury goes a step further: each of its accounts also carries its own separate routing number, making it fully independent from the others.
Each account can send and receive wires and ACH transfers independently. Each shows up separately on a bank statement, and each can be shared with a different person, so one team member can see only the payroll account.
Bluevine and Baselane sit in between. Each sub-account gets its own dedicated account number but shares the parent account's single routing number.
That's useful if you want to hand a vendor or a property manager a specific account number for rent or invoice payments, without opening a fully separate account.
None of this changes what the money can do. It changes how visible, how shareable, and how separately trackable each bucket is.
At-a-glance comparison
Provider | Sub-accounts allowed | Cost | Account number structure | What they call it | Best for |
|---|---|---|---|---|---|
Novo | No hard published cap; Novo's own copy says most small businesses use three to six | $0 monthly fee and no minimum balance requirement for the business checking account or Reserves | Shares the parent account's single routing and account number | “Reserves” | Straightforward budgeting inside one account, no per-bucket account numbers needed |
Bluevine | Standard: up to 5. Plus: up to 10. Premier: up to 50 | Standard $0/month (no waiver needed). Plus $30/month (waivable). Premier $95/month (waivable) | Each sub-account gets its own dedicated account number, shared routing number | “Sub-accounts” | Businesses that want a dedicated account number per bucket, e.g. for routing specific payments |
Relay | Up to 20 checking accounts | No monthly maintenance fees or minimum balances on the accounts themselves | Each account has its own unique account number | Doesn't use “sub-accounts” branding; just calls them checking accounts | Teams that want fully separate, independently shareable accounts rather than internal buckets |
Baselane | Unlimited checking and savings accounts | $0 monthly account maintenance, $0 minimum balance | Each sub-account gets its own unique routing and account number | “Sub-accounts,” built around individual properties | Landlords and real estate investors tracking cash per property |
Mercury | Up to 100 checking and 100 savings accounts | No additional cost to open extra accounts | Each is a full, separate checking account with its own unique account number | No dedicated feature name; Mercury recommends opening more accounts | Businesses comfortable managing several fully separate accounts without a bucket-style dashboard |
Now that you know the mechanics, here's how each provider actually builds it.
The providers, one at a time
Novo Reserves
Novo built its sub-account feature, called Reserves, directly into its free business checking account rather than as an add-on. It's the simplest version of the feature covered here: pick a name, set a target if you want one, and move money in and out from your main checking balance.
Key features:
No hard published cap on the number of Reserves. Novo's own copy says most small businesses use three to six.
Reserves share the parent account's single routing and account number. They are not separately addressable accounts and do not expand FDIC coverage beyond the parent account's $250,000.
Money moves between checking and Reserves instantly inside Novo's own app.
Pricing: $0 monthly fee and no minimum balance requirement for the business checking account or Reserves.
Pros:
Free, with no tier to upgrade into for more Reserves.
Simple enough to set up in minutes, no separate application per bucket.
Cons:
No dedicated account number per Reserve, so you can't hand one out for someone to pay into directly.
Novo has no savings or CD product. Reserves is strictly a within-checking budgeting tool, not a place to earn yield on the cash you're setting aside.
Who it's for: Solo founders and small teams who want a clean visual split between spendable cash and money already earmarked, without needing separate account numbers for any of it.
Bluevine sub-accounts
Bluevine's sub-accounts scale with its checking plan tiers, and each one gets its own account number even though they all share the same routing number. That makes them usable for more than internal labeling.
Key features:
Standard plan: up to 5 sub-accounts. Plus: up to 10. Premier: up to 50.
Each sub-account carries the same feature set as the main account: ACH, wires, checks, and FDIC pass-through coverage through Bluevine's bank partners.
A dedicated account number per sub-account means you can route a specific payment, like rent from a specific client, straight into the right bucket.
Pricing: Standard $0/month, no waiver needed. Plus $30/month, waivable. Premier $95/month, waivable.
Pros:
Free tier still gets 5 sub-accounts, more than most businesses need to start.
Dedicated account numbers per bucket, useful for directing specific incoming payments.
Cons:
The jump from 10 sub-accounts (Plus) to needing more means paying for Premier at $95/month, waivable but still a real plan change.
Shared routing number means these aren't fully independent accounts if you need that level of separation.
Who it's for: Businesses that want more buckets than Novo's casual approach implies, with the option to hand out real account numbers, and that are fine scaling into a paid tier as the number of buckets grows.
Relay
Relay doesn't call this feature “sub-accounts” at all. Its approach is simpler to describe: open more full checking accounts, up to 20, each with its own account number.
Key features:
Up to 20 checking accounts, each with its own unique account number and behaving like a standalone checking account.
No monthly maintenance fees or minimum balances on the accounts themselves.
Pricing: No monthly maintenance fees or minimum balances on the accounts themselves.
Pros:
Full account independence: each one can be shared with a different team member, or connected to a different accounting integration, without exposing the rest.
No fee ceiling to hit as you add accounts, unlike a tiered sub-account plan.
Cons:
Managing 20 separate account numbers and statements is more operational overhead than a single dashboard with internal buckets.
Relay's own published materials disagree on whether account limits vary by plan tier; the flat “up to 20” figure is the only one confirmed live across both of Relay's own pages on this feature.
Who it's for: Agencies and teams who want real account-level separation, not just visual budgeting labels, and don't mind the extra accounts showing up as separate lines everywhere.
Baselane
Baselane built its version of sub-accounts specifically for landlords and real estate investors tracking income and expenses property by property, which is a different use case from the general small-business budgeting the other four providers target.
Key features:
Unlimited checking and savings accounts, with no cap tied to a plan tier.
Each sub-account gets its own unique routing and account number, not a shared-routing internal bucket.
Built to map one sub-account to one rental property, so rent, repairs, and reserves for that specific unit stay separate from every other property.
Pricing: $0 monthly account maintenance, $0 minimum balance. Banking services provided by Thread Bank, Member FDIC.
Pros:
No limit on how many properties or buckets you can track, which matters once a portfolio grows past a handful of units.
Dedicated account and routing numbers per sub-account, so tenants can pay directly into the right one.
Cons:
The feature is built around the property use case specifically; a business with no real estate to track gets less out of the property-level framing.
Whether Baselane's sub-account structure changes FDIC coverage beyond the standard $250,000 per depositor isn't published anywhere we could independently verify, so don't assume it works like Novo's (which explicitly doesn't expand coverage) or make any other assumption without checking directly with Baselane.
Who it's for: Landlords and real estate investors who need per-property cash tracking, not general small-business budgeting.
Mercury
Mercury doesn't have a dedicated sub-account or envelope feature. Its own guidance, published on its blog, is to open more full checking accounts instead, and use each one as a budgeting category.
Key features:
Up to 100 checking accounts and 100 savings accounts, each a fully separate account with its own unique account number.
No dedicated budgeting UI or “bucket” dashboard. Each account is managed like any other checking or savings account.
No additional cost to open extra accounts.
Pricing: No additional cost to open extra accounts.
Pros:
The account cap (100 of each type) is high enough that almost no business would hit it.
Every account is a full, independent account, useful if you want hard separation rather than internal labels.
Cons:
No visual budgeting layer. You're tracking buckets across separate account dashboards rather than one unified view.
More accounts means more statements and more reconciliation work at tax time, since there's no consolidated envelope view.
Who it's for: Businesses that are already comfortable managing multiple full bank accounts and don't need a dedicated budgeting dashboard to make that workable.
Which one fits your business
Novo: the simplest version of this, with no dedicated account numbers per bucket needed. Reserves are free.
Bluevine: more buckets with the option of real account numbers attached. Sub-accounts scale from free up through Premier as your needs grow.
Relay: fully independent accounts you can share selectively with different people. Up to 20 checking accounts, no shared-routing bucket model.
Baselane: built for tracking rental properties specifically. Unlimited, property-mapped sub-accounts, not general business budgeting.
Mercury: for businesses already comfortable managing several separate accounts. Up to 100 accounts, just without any envelope-style UI.
None of these five will fit every business. If you want the fuller field, including providers that don't build a dedicated sub-account feature, our full comparison of business bank accounts covers the major players.
FAQs
Novo, Bluevine, Relay, and Baselane all offer some form of sub-accounts for budgeting inside a business checking account. Novo calls them Reserves, Bluevine and Baselane call them sub-accounts, and Relay builds the same idea as separate checking accounts rather than internal buckets.
Mercury doesn't offer a dedicated sub-account feature; it recommends opening additional full checking accounts instead.
A sub-account is a division of cash inside your main business checking account, used to earmark money for a specific purpose like taxes, payroll, or a project, without opening a new legal bank account. Novo (Reserves), Bluevine, and Baselane all call this “sub-accounts” or a close variant. The money stays inside your existing account; the bank's dashboard just tracks each labeled portion separately from the rest.
A sub-account typically shares your main account's routing number, and sometimes its account number too, as with Novo's Reserves. Opening multiple full checking accounts, which is Relay's and Mercury's approach, gives each one its own separate account number and behaves like an entirely independent account.
Bluevine and Baselane split the difference: each sub-account gets a dedicated account number but shares the parent's routing number.
Novo, Bluevine, Relay, and Baselane each offer some version of it, though Relay doesn't use the term “sub-accounts” and instead lets you open up to 20 full checking accounts. Mercury doesn't have a dedicated sub-account feature at all; it recommends opening additional full checking accounts (up to 100) instead.
Yes. There's no legal restriction on how many business bank accounts a single LLC can hold, at one bank or across several. That's exactly the mechanism Mercury and Relay lean on: rather than building an internal budgeting feature, they let you open as many full accounts as you want under the same business.
Mostly, yes, with one exception. Novo's Reserves and Baselane's sub-accounts are both free with no monthly fee or minimum balance. Bluevine: Standard $0/month, no waiver needed. Plus $30/month, waivable. Premier $95/month, waivable. Relay's checking accounts carry no monthly maintenance fee or minimum balance at the account level.
It depends on the provider. Novo's Reserves share the parent account's single routing and account number entirely. Bluevine's and Baselane's sub-accounts each get a dedicated account number but share one routing number. Relay gives every account its own account number; Relay's own materials disagree on whether routing numbers are shared or separate across accounts, so we're not asserting one here. Mercury's accounts are each fully separate, with their own account and routing numbers.
Not automatically, and this varies by provider in ways that aren't all publicly documented. Novo states directly that Reserves do not expand FDIC coverage beyond the parent account's $250,000.
Whether Bluevine's or Baselane's per-sub-account account numbers change how coverage is calculated isn't something we could independently verify from either company's public pages, so don't assume parity between providers. If protecting balances above $250,000 matters to you, ask the bank directly rather than assuming.
It ranges from unlimited (Baselane) to a soft norm rather than a hard cap (Novo, where most businesses use three to six Reserves) to a tiered limit that scales with your plan (Bluevine: 5, 10, or 50). Relay caps at 20 full checking accounts, and Mercury caps at 100 checking and 100 savings accounts, though neither of those two frame it as a “sub-account” limit specifically.
No, and this is a common point of confusion. A single linked savings account is one destination for excess cash, funded from and withdrawn back to your primary checking account, and it's not a multi-bucket system: you can't split it into a “taxes” pile and a “payroll” pile the way Novo's Reserves or Bluevine's sub-accounts let you.
Rho, for example, offers one linked Business Savings Account per entity, funded and withdrawn from your primary checking account only, useful for parking cash you're not actively spending but not a sub-accounts or envelope-budgeting feature.