How it works

The sweep account

It is a normal checking account

This is the part people expect to be complicated and it is not. The account has a routing number and an account number. Direct deposit works. Automatic bill pay works. Debit purchases work. Transfers to and from other institutions work.

Nothing about how you actually run your week has to change.

What the sweep does

At the end of each day, whatever is sitting in checking is swept onto the line. Money is never idle overnight, which is the whole reason the account exists.

The next morning, whatever you spend draws back off the line. The mechanics run themselves.

Why this matters for the strategy

In a conventional setup your paycheck sits in checking, earning close to nothing, while a separate mortgage accrues interest on its full balance. The two accounts do not know about each other.

The sweep closes that gap. The money is in one place, and while it sits there it is reducing the balance interest is calculated on.

It is worth being clear about the size of this effect. Sweeping does not create money. It changes how many days your cash spends reducing the balance rather than sitting still, and on a large balance those days add up. But the strategy is still driven by the surplus — the sweep is what makes applying that surplus automatic rather than something you have to remember to do.

What it does not do

It does not protect you from overspending. Money drawn off the line is money drawn off the line, whether the sweep is running or not.

It does not change the rate, and it does not change what you owe. It changes the timing of when your cash is working against the balance.