When Does a CD's Rate Actually Lock In?
An advertised CD rate can look tempting on a bank’s website, but that number isn’t necessarily the one that ends up on the account. There’s a specific moment when the rate actually becomes fixed.
The short answer
A CD’s rate typically locks in when the account is opened and funded, not when it’s first viewed or even when an application is submitted. Rates advertised online are usually subject to change until money actually lands in the account, so a delay between application and funding can mean a different rate applies.
Why the gap matters
Banks adjust CD rates based on broader funding needs and market conditions, sometimes with little notice. A rate seen on a comparison page one day might be different a few days later if the bank has updated its offerings. This is different from, say, a mortgage rate lock, which is often a formal, contractual guarantee held for a set number of days. CD rates generally don’t come with that kind of advance lock — the rate that applies is usually whatever is in effect at the moment funding is completed.
The typical sequence
- Viewing the rate. The advertised rate is informational and can change at any time before an account is opened.
- Applying or opening the account. Some institutions lock the rate at this step, but many state clearly that the rate isn’t final until funds are received.
- Funding the account. This is usually the point of no return — once money is deposited and the CD is active, the rate that was in effect at that moment is the one that applies for the term.
Reading the specific disclosure for a given CD offer is the only reliable way to know exactly which of these steps determines the final rate at a particular bank, since practices aren’t identical everywhere.
What happens if funding is delayed
If there’s a lag between opening an account and actually transferring the money in — for instance, waiting on a wire transfer or an ACH transfer from another bank — the rate that ends up on the CD may reflect whatever was current at the time the funds cleared, not the rate quoted when the paperwork started. In a period of shifting rates, that gap could work in either direction: the funded rate could end up higher or lower than what was originally advertised.
Promotional and limited-time offers
Rates tied to a promotional window are especially sensitive to timing, since these offers often carry an explicit deadline or funding requirement. Missing that window can mean falling back to the bank’s standard rate instead of the promotional one, even if the application itself was submitted while the promotion was live.
The takeaway
The number seen while shopping for a CD is a snapshot, not a promise, until the account is actually opened and funded. Anyone comparing offers across institutions should pay attention not just to the headline rate but to how quickly funding needs to happen to actually secure it, since a slow transfer could mean the rate that gets locked in isn’t the one that first caught their attention.