A letter shows up from your card issuer. Your limit is lower, or your rate has a new number on it. Your first thought may be that you did something wrong. Often the cause is an account review, and the rules around it are more specific than most people expect.

What a credit card account review is

An account review is the issuer's ongoing check on how an open account is being managed. Think of it as a look at your balances, your payment history, and how much of your available credit you are using. The review can end with no change at all. It can also lead to a higher or lower limit, a new interest rate, or other changes to your terms.

The sources I used do not say how often issuers run these reviews. So timing is unclear, and a change can feel like it came from nowhere. The best habit is simple. Read your card agreement, and read every notice the issuer sends.

Why your interest rate may change

Start with the notice rule. Issuers can usually raise your rate with 45 days' advance notice. The CFPB also explains that they generally cannot raise the rate on your existing balance, except in a few named cases.

There is a first-year rule too. Issuers generally cannot raise the rate on new transactions during the first year of the account. After a rate-change notice, purchases made more than 14 days later count as new transactions. That is why the date on the notice matters.

Here are the cases where the rate on an existing balance may go up. Keep them handy, because they work like a checklist.

  1. A temporary rate ends. A low balance-transfer rate, for example, must last at least six months. When it expires, the rate on that balance may rise.
  2. A variable rate moves. A variable rate follows an index, such as the U.S. Prime Rate. If the index rises, your rate can rise with it.
  3. A payment is very late. The rate may rise if no minimum payment arrives within 60 days after the due date.
A printed card statement and a folded rate-change letter sit side by side on a bright kitchen table, with a red-circled date on the letter.
A card statement and a rate-change notice laid side by side on a kitchen table, with the effective date circled.
  1. An arrangement to lower your rate ends. The rate may rise after you complete the arrangement or fail to follow it.

A rate increase on an existing balance that fits none of these deserves a closer look.

Why your credit limit may change

Issuers generally can raise or lower your limit. A cut can be large. It can even leave you with no available credit. If that happens, you cannot make new charges until you pay down part of the balance.

One protection helps here. Over-limit fees and penalty rates for going over a lowered limit cannot be charged until 45 days after notice of the decrease. That gives you time to adjust.

Experts commonly advise keeping your use at no more than 30 percent of your total limit. That cushion can help if a limit drops. It can also support your credit score. The sources do not say how fast a limit change shows up in a score, so I will not guess.

Notices, opt-outs, and your rights

For unfavorable changes, like a lowered limit or a closed account, issuers generally must send an adverse action notice. That is a notice telling you a decision went against you. It should give specific reasons or explain how to ask for them. The FTC has guidance on these notices, but the page I had did not spell out their contents.

Significant changes generally need 45 days' notice. These include certain rate and fee increases, a higher minimum payment, and changes to the grace period or how interest is calculated. Changes to rewards or the card brand are generally not significant, so you may get less warning.

For many changes you can opt out. The issuer might then close the account. You would not owe the balance all at once, but you must keep paying until it is paid in full. Closing can also reduce your available credit, which may hurt your score.

If your minimum payment rises, the new amount generally cannot go past the larger of two figures. One is the amount that would pay off the balance in five years. The other is double the old minimum. The sources do not cover Servicemembers Civil Relief Act protections in detail, or state rules.

Questions to ask and warning signs

When something changes, go step by step. Ask whether you got 45 days' notice. Ask whether the change hits new purchases or the existing balance. Check whether your rate is variable and whether its index rose. Check whether your balance sits near 30 percent of your limit.

Some things are worth writing down. One is an over-limit fee or penalty rate after a limit cut with no notice. Keep the statement and the date. If you get an adverse action notice, read the stated reasons slowly.

The sources do not explain how to ask for a higher limit or a lower rate. For that, go to the regulator pages directly, or talk with a qualified professional. This article is education, not advice for your situation.

Please seek a professional. This article is general information, not financial, tax or insurance advice. Please seek a licensed financial, tax or insurance professional about your own situation.