And remember, it's not when you postmark the payment that counts. It's when it's received. If you're considering taking advantage of a teaser rate offer, you'll naturally want to compare rates. Most are will hold the lower rate for 5 or 6 months. Make sure that the lower rate will apply not only to the balance that you transfer, but also to any new purchases you make during the introductory period.
Many cards charge their regular, higher rate for new charges.
There's more to consider than interest rates. Don't forget annual fees. Avoid 'cash advance' charges to move your balance. Some issuers offer a nice rate, but will charge you a couple of percentage points or more to transfer your balance. They consider it a 'cash advance'.