What does a custodian actually do?
The custodian is the account's legal administrator. It opens your self-directed IRA, receives the transfer or rollover that funds it, executes your purchase instructions, holds title to the metal on your behalf, and files the required IRS reporting every year.
What a custodian does not do is sell you metal or give investment advice. You choose the dealer and the products; the custodian processes the paperwork and keeps the account compliant.
Why does the custodian matter to your costs?
Custodians charge their own fees, account setup, annual administration, and sometimes transaction fees, entirely separate from the premium you pay the dealer and the storage fee you pay the depository. Three parties, three cost layers.
Fee structures differ: some charge flat annual fees, others scale with account value. On a metals position you intend to hold, the difference compounds into real money over a decade, so compare published fee schedules before opening the account.
How does the custodian show up in practice?
In a typical Gold IRA, you open the account with the custodian, fund it by transfer or rollover, then direct the custodian to send funds to your chosen dealer. The dealer ships the metal to the depository, and the custodian records it in your account.