The information a consolidation offer is designed not to give you is the total. A consolidation is sold on the monthly payment, because that is the number that falls immediately and visibly. The payment can fall for two completely different reasons: because the rate dropped, or because the term got longer. Only the first of those saves money, and the second can cost a great deal while feeling identical. The Consumer Financial Protection Bureau's warnings on consolidation offers are worth taking literally, and there are three: a lower monthly payment may simply mean you are paying over a longer time, so you can pay considerably more overall once fees are counted; many advertised low rates are temporary and expire; and consolidating unsecured balances into home equity borrowing introduces the risk of losing the house. The test that follows from all three is to compare total cost against total cost, and never payment against payment.
The ranking question the category actually poses, and it is not about the rate. Debts differ in what happens when they are not paid, and consolidation can change that answer. An unsecured balance is enforced by collection and, if the creditor sues and wins, by a judgment; it is dischargeable in bankruptcy in the ordinary way. The same balance moved onto a home equity loan or line is enforced against the house. That is a genuine improvement in price and a genuine reduction in your options, purchased together, and the price is cheaper precisely because the lender's remedy is better. So before comparing two offers on cost, sort them by what they put at risk. Rate differences of a few points are recoverable; a foreclosure is not.
The routes, and the question to ask of each. A balance transfer moves card balances onto another card, usually at a promotional rate for a stated window and for an upfront fee, so its question is whether the balance will actually be gone before the window closes. A personal loan is unsecured closed-end credit on a fixed amortizing schedule, so its question is the term, because a longer one lowers the payment and raises the total. A home equity loan or home equity line of credit is secured by the residence, so its question is the one above about consequences. A debt management plan arranged through a nonprofit credit counseling agency is not new credit at all; the agency negotiates concessions with existing creditors and administers one monthly payment, so its question is what the agency charges and what the creditors have actually agreed to. And federal student loan consolidation is a different legal instrument that happens to share the word, discussed below.
Consolidating does not close anything, and the accounts that stay open are a live question in both directions. Paying a card to zero leaves the account open with its full limit available, which is how a household ends up with a consolidation loan and, a year later, a fresh set of card balances beside it. But closing the cards is not automatically the right response either, because removing their limits raises the share of your available revolving credit that your remaining balances represent, and the published material on credit utilization covers what that does. The honest answer is that consolidation works when it is the last step of a plan that already deals with why the balances appeared, and that the decision about the old accounts belongs to that plan rather than to the consolidation.
One right that travels with a consolidation and is easy to leave on the table. Where a loan being paid off is a precomputed consumer credit transaction, 15 USC 1615(a)(1) requires the creditor to refund promptly any unearned portion of the interest charge, and (a)(3) states expressly that the right applies "without regard to the manner or the reason for the prepayment," naming a prepayment made in connection with a refinancing, consolidation or restructuring. So the old loan's unearned interest is yours, and it should appear in the payoff figure rather than being quietly absorbed.
A naming point, because one federal instrument uses the same word for something else. A Direct Consolidation Loan is a specific statutory federal student loan that combines existing federal loans into one new federal loan. It is not consumer debt consolidation, and it has consequences that have no analogue here, including resetting progress toward loan forgiveness and, in some cases, changing which repayment plans are available. Consolidating federal student loans through a private lender is a third thing again, and it permanently gives up the federal protections. The published material on federal student loans and student loan refinancing covers those; this page is about consumer debt.