Your account application with our partner bank is prepared for you as part of plan setup. What follows is what a bank asks for and why, which matters most if you open the account at an institution you choose yourself.
What type of account do I need?
You need a trust account or commercial account, not a personal retail account. Your Solo 401(k) is a qualified employer retirement plan with a trust that holds plan assets, and that trust is a separate legal entity with its own EIN.
Terminology varies by institution. Some call these trust accounts, others call them commercial or business accounts. The concept is the same: an account for an entity rather than for an individual.
What documents does the bank need?
You will provide either your Trust Agreement or a Certificate of Trust. The Certificate of Trust is a condensed version showing the trust's name, date, trustees, and powers, without reproducing the full trust provisions.
Many banks accept the Certificate of Trust because it is shorter and easier to review. Some require the full Trust Agreement. Ask which the bank prefers before you apply.
You will also need the plan trust's EIN, which is the plan's own EIN and never the sponsoring business's EIN.
Who signs for the account?
You sign as trustee. You are opening the account on behalf of the plan trust, not as an individual depositor.
The bank will verify your identity through standard "Know Your Customer" procedures: photo ID, address verification, and the usual account opening paperwork. Your signature authority comes from your role as trustee, documented in the Trust Agreement or Certificate of Trust. The bank may ask to see the section granting that authority.
Where the opening deposit comes from
Every dollar that enters this account must be plan money, arriving either as a rollover from another retirement plan or IRA, or as a contribution from the sponsoring business. You cannot make an opening deposit from personal funds, even a small one, and even if the bank asks for it as a condition of opening the account.
If an institution requires a personal deposit to open, that requirement cannot be met and the account cannot be opened there. Funding arrives once the account exists.
What banking services can I use?
You can access standard banking services: checks, debit cards, online banking, mobile banking, wire transfers, and ACH transactions.
Credit instruments are the exception, and the caution here is firm. The plan trust cannot accept a credit card, line of credit, overdraft protection, or any other feature that extends credit to the account. Each of these requires your personal guarantee, and a guarantee is an extension of credit between the plan and a disqualified person, which IRC Section 4975 prohibits.
Banks offer these products routinely at account opening, often as a package. Decline them at the point of offer rather than accepting and unwinding later.
Opening more than one account
A Solo 401(k) can hold as many bank accounts as the plan needs, and every account is titled in the plan's name regardless of how many there are. Opening a second or third account follows the same process as the first, using the same plan documents and the same plan EIN.
Plans with more than one participant, or with more than one tax treatment in use, often open a separate account for each. That choice is driven by recordkeeping rather than by banking, since the plan must be able to show the value of each participant account at any point in time.
If you know you will need several accounts, open one and get it fully established first. Most banks make additional accounts far simpler once a relationship exists, since the plan documents are already on file and your identity is already verified.
Frequently Asked Questions
When can I open the bank account?
Once you receive your plan documents. That delivery includes the Trust Agreement, the Certificate of Trust, and the plan's EIN, which together are everything a bank will ask for.
If my spouse participates in the plan, will they need to sign?
Only if you want them to have signing authority on the bank account. A participant who will transact on the account provides their personal information to the bank and signs the account agreements alongside you. Participating in the plan and signing on a bank account are separate things, and one does not create the other.
What if I need to make changes to signers later?
Provide an amended Certificate of Trust or a trustee resolution to the bank showing the updated authorization.