What a subaccount is
A subaccount is a bucket that lives insidea real account. Your bank sees one balance; ReadyCents shows the split, like a “Round-Ups” bucket nested under checking or an “Emergency” slice inside savings. No new bank account, no new login, just a fence around money you don't want to accidentally spend.
Create one from Add Account → Add an Unlinked Account → Subaccount of, or on mobile open the parent account's menu and tap Add Subaccount.
Round-up sweeps
If your bank does round-up savings (Acorns-style, where every swipe moves spare change), give the subaccount a Roundup Sweeprule: “when a transaction in the parent account matches this payee and direction, move it here automatically as a transfer.” Matching uses payee and direction, never the amount, so it keeps working when the round-up size changes.
Moving money and transactions
Money moves between a parent and its subaccounts with ordinary transfers. There is no income or expense, just relocation. Already-recorded transactions can be moved too: select them in the register and use Move to subaccount. Balances always add up: parent + subaccounts = what the bank says.