Gather your most recent Discover Card statement and review it for your current interest rate.
Identify your account number and find the contact number for customer service.
If you have statements for the past several months to a year, or more, review those statements to spot trends which may identify why your interest rate has gone up. That may include late payments on your part or a decision by Discover Card to simply raise their rates.
Contact other credit card providers to learn what their rates are; you will need to have this information handy when you make your phone call to Discover.
Be prepared to have an interest rate in mind when contacting Discover Card. If you are currently paying 18 percent on your balance, ask for a much lower rate to begin with.
Tell Discover's representative that you want a lower interest rate; ask if they would drop your current rate to 6 percent.
If this person does not have the authority to change your rate, ask to speak to someone who does.
Be polite while articulating what you want. Discover Card doesn't have to lower their rate, but if you explain to them that you are determined to get your finances in order and are weighing offers from competing credit card providers, then they may counter your offer with a lower rate. Your goal is to have your current rate reduced as much as possible.
Politely state your case and ask for a lower rate if their counter offer isn't satisfactory. If you are happy with the new rate, then you have gotten what you wanted. If you're not happy, but have managed to get Discover Card to lower their rate, then accept their offer.
Confirm your new, lower interest rate on your next Discover card statement. If your rate hasn't been lowered, call customer service again, and inform Discover Card that the promised rate has not been applied.