Bank Accounts for a Series LLC: One Account Per Series?

Does each series need its own bank account?

No federal rule requires it. The liability wall each series statute creates depends on separate records and unmingled funds, so a series holding meaningful assets is banked separately in practice by nearly everyone who takes the structure seriously.

Nothing in the Internal Revenue Code or in any series statute says a series must hold its own account. What the statutes say is that assets associated with a series are shielded from the liabilities of other series only where records identify those assets clearly and the assets are held separately.

A shared account is the single easiest way to fail that test. Rent from series 1 and series 3 landing in the same account, paying expenses of series 2, is precisely the fact pattern a creditor's lawyer looks for, and it is visible in 1 statement rather than requiring discovery.

The counter-case is genuine and worth stating. A structure whose series exist for administrative tidiness rather than asset protection, reporting through the master on 1 return with 1 set of books, has nothing to gain from 5 accounts and 5 EINs. The banking decision follows the asset-protection intent.

Once the decision to bank separately is made, the EIN follows automatically. An account in a series name needs an EIN in that series name, so the trigger list and the banking plan cannot be decided independently.

What does a US bank verify for a series account?

3 documents in a fixed order: the state formation record, the CP-575 or 147C letter carrying the 9-digit EIN, and the governing agreement naming the series and its authorized signer. All 3 names have to match character for character.

The formation record comes first because it establishes what exists. For a Delaware registered series or an Illinois designated series that is a state certificate. For a Texas or Nevada series it is the certificate of formation for the master plus the company agreement, because the state holds nothing series-specific.

The IRS letter comes second and is the one that stops applications. A CP-575 is issued once, at EIN assignment, and carries the name from line 1 of Form SS-4. A 147C letter is the replacement and is accepted equally. A series with no letter in its own name cannot open an account in its own name, whatever the state documents say.

The governing agreement comes third and does 2 jobs: it names the series, and it names who is authorized to sign for it. Banks read the signature authority as carefully as the name, because an account opened by someone the agreement does not authorize is a compliance problem for the bank rather than for the owner.

Onboarding stalls of 5 to 10 business days come almost entirely from name mismatches across those 3 documents. LLC against L.L.C., a missing comma, or a truncated Illinois series name is enough to hold the application at verification.

Why does a series account force an EIN?

Because the bank has to report interest and comply with customer identification rules against a taxpayer identification number, and the only entity-level number the IRS issues is the EIN. An SSN identifies a person, not a series.

US banks operate customer identification programs that require a taxpayer identification number for every account holder. For an entity account that means an EIN, verified against an IRS document rather than against the applicant's word.

Interest reporting runs on the same number. A business account paying interest generates a Form 1099-INT under the account holder's EIN, and an account titled to a series but reporting under the master's number produces a mismatch between what the bank filed and what the master's return shows.

This is the point at which the unresolved federal question stops being theoretical. The IRS has never finalized whether a series is a separate entity, but a bank cannot open an account against an unresolved question, so it asks for the number and the structure supplies it. In practice, banking demand drives more series EIN applications than tax analysis does.

None of this costs anything at the IRS. Each EIN is $0 on all 4 channels, and the constraint is the 1-per-responsible-party-per-day cap rather than money, so a structure opening 4 series accounts plans 4 business days of applications.

What document set does each series account need?

5 items: the state formation record, the series certificate or the agreement clause creating it, the CP-575 or 147C, government ID for the signer, and a resolution naming that signer. Fintechs ask for the same 5 as branch banks.

Assemble the set before the appointment rather than during it. Every item on the list is obtainable in advance, and the 2 that take time are the ones people leave until last: an EIN takes 15 minutes online or 4 to 7 business days by fax, and a 147C replacement takes a phone call plus same-day fax.

Fintech onboarding is not lighter here, despite the reputation. Mercury, Wise and Relay each verify the same EIN and IRS letter as Chase or Bank of America, and their automated name matching is stricter than a branch officer's, because there is no human to accept an obvious equivalence.

Foreign-owned series add 1 step rather than a different process. The responsible party on line 7a can be a non-US person with the entry Foreign on line 7b, and the resulting CP-575 is accepted normally. What varies is the bank's own policy on non-resident account opening, which is a separate question from the EIN.

Keep a digital copy of every CP-575 the structure holds on the day it arrives. The IRS prints each one once, and a structure with 6 EINs has 6 irreplaceable letters, each recoverable only as a 147C.

Source: IRS Instructions for Form SS-4 and the published account-opening requirements of Mercury, Wise, Relay, Chase and Bank of America, verified August 2026. Bank policies vary and change; confirm with the institution before the appointment.

What happens if series funds are commingled?

The liability wall is what is at risk, not the tax treatment. Every series statute conditions the shield on records that identify each series' assets, and a shared account is the clearest available evidence that no such separation exists.

State statutes are consistent on this point even where they differ on everything else. Delaware, Texas, Nevada and Illinois all condition the inter-series shield on maintaining records that account for the assets of each series separately. A single account holding everything defeats that on its face.

The tax consequence is milder and more immediate. Funds belonging to series 2 sitting in series 1's account, reported under series 1's EIN, misstate which entity received the income. Correcting that after the fact means amended returns for each affected year rather than a single fix.

Partial separation is the common real-world state and the worst of both. A structure with 3 accounts for 5 series has neither the simplicity of 1 nor the defensibility of 5, and it is harder to explain to a court than either.

The workable rule is to make the banking match the intent. Series that exist to hold risk apart get their own accounts and their own EINs. Series that exist for internal reporting bank through the master and take no number.

Can every series share the master LLC's account?

Yes, and it is the correct answer for structures whose series are administrative rather than protective. 1 account, 1 EIN, 1 return, and the series exist as internal bookkeeping divisions.

This configuration is legitimate and underused. An owner with 6 properties who wants tidy per-property reporting, not a liability wall, gets that from a chart of accounts rather than from 6 bank accounts and 6 EINs. The structure stays simple and the federal filing count stays at 1.

The trade is explicit: those series are shielded from each other in state statute only to the extent the records support it, and shared banking undercuts the record. An owner choosing this route is choosing reporting convenience over asset protection, and should choose it deliberately.

The mixed case works too. A structure can bank series 1 and 2 separately because they hold real estate, and run series 3 through 6 inside the master because they hold nothing at risk. That is 3 EINs, not 7.

What does not work is claiming the protection while running the shared account. The wall depends on the record, and the account statement is the record a creditor reads first.

How do you open the first series account, step by step?

5 steps: confirm the series exists in the governing document, file Form SS-4 for that series, wait for the CP-575, assemble the 5-item document set, then open the account in the exact name on the letter.

Step 2 is where the daily cap bites. The IRS issues 1 EIN per responsible party per day, so a structure opening 3 accounts files across 3 business days, or names a filing agent on line 18. Planning that in advance turns a 3-week sequence into a 3-day one.

Step 3 is the one with the longest tail for foreign owners. An applicant with an SSN or ITIN gets the number on screen in about 15 minutes. An applicant using the fax route waits 4 to 7 business days for the number and the letter, and mail runs 6 to 11 weeks.

Step 5 is where character-for-character matching matters. The name on the account application has to be the name on the CP-575, which is the name from line 1 of Form SS-4, which should be the name in the state certificate or the governing agreement. A break anywhere in that chain stalls the application.

If the CP-575 is already lost by the time the account is opened, request a 147C rather than reapplying for a new EIN. The number is unchanged, the letter is free, and a second EIN for the same series creates a duplicate the IRS then has to close.

Who should pay anyone to file this?

An applicant holding an SSN or ITIN pays nobody. The IRS online assistant issues each EIN in about 15 minutes for $0. An applicant without either uses the fax route, also $0, or hands it to someone.

Price context, so the $97 is legible. The IRS charges $0 for the EIN itself and it never renews, so year 2 and every year after costs $0. Formation companies price it as an add-on: Northwest at $200 without an SSN, ZenBusiness at $99, Rocket Lawyer at $59.99, all verified July 2026. None of the 3 publishes a written filing deadline, and none reviews the SS-4 classification lines before filing. Full breakdown on LLC EIN cost.

What else do owners ask about banking a series LLC?

8 questions come up most: whether each series needs an account, whether an account forces an EIN, what banks verify, whether fintechs are easier, and what commingling costs.