What Custom Cash lets you do

Custom Cash is a feature on certain American Express cards that lets you choose which spending categories earn your highest cash-back rate. Instead of being locked into fixed categories like "groceries" or "gas," you pick the one category that matters most to your budget, and that's where you earn bonus cash back each month.

The card comes with a base cash-back rate on all purchases, then you layer on a higher rate for whichever single category you choose. You can change your choice each month if your spending shifts — say, switching from "streaming services" in January to "home improvement" in March when you're renovating.

This matters because most people's spending doesn't fit neatly into the categories card issuers pick for them. If you spend heavily on something outside the standard buckets, Custom Cash lets you capture that higher rate where it actually helps your wallet.

Key Takeaways

  • You pick one category each month to earn a higher cash-back rate; all other purchases earn a lower flat rate.
  • The category list is set by American Express and includes common spending types like dining, gas, transit, and streaming — but not every possible category.
  • You change your category choice through your online account or the American Express mobile app, and the change takes effect when ready.
  • If you forget to pick a category, the card defaults to a standard category, so you don't lose the bonus entirely — but you may not earn the rate that would help you most.

How to choose and change your category

Log into your American Express online account or open the mobile app. Look for the Custom Cash settings — this is usually in the card management or rewards section, not buried in account settings. You'll see a list of available categories: dining, gas stations, transit, streaming services, transit, and a few others depending on the specific card version.

Select the category where you spend the most money in a typical month. The change takes effect right away, so any purchases in that category from that point forward earn the higher rate. You can change your choice as often as you want — daily if you wanted to, though that's not practical — but the change only applies to future purchases, not past ones.

If you don't actively choose a category, American Express assigns a default one automatically. Check what it is so you know whether you're earning the rate you want. Many cardholders miss out on cash back straightforward because they never logged in to make a choice.

Which categories are available

American Express publishes the category list on the card's benefits page, and it changes slightly depending on which Custom Cash card you hold. Common options include gas stations, restaurants and dining, streaming services, transit (including taxis, rideshare, and public transportation), and home improvement stores.

The list is fixed — you can't create a custom category that isn't on the menu. If your biggest spending is on something like pet supplies or office equipment, and that's not listed, you'll earn the base rate on those purchases instead. Before you open the card, check whether your top spending category is actually available.

How the cash-back rates work

The card structure is typically a base rate — often 1% cash back — on all purchases, plus a higher rate on your chosen category. That higher rate is usually 3% or higher, depending on the card. So if you choose dining and spend $500 at restaurants in a month, you earn $15 in cash back on those purchases, while a $200 grocery purchase earns $2 at the base rate.

Cash back posts to your account monthly and can be redeemed as a statement credit, transferred to certain travel partners, or held in your rewards account. There's no cap on how much you can earn in a month, and there's no annual limit — you keep earning on every purchase in your chosen category all year.

When to change your category choice

Change your category at the start of each month, or whenever your spending patterns shift noticeably. If you know December will be heavy on dining because of holiday meals and parties, switch to that category in November or December. If you're doing a kitchen renovation in spring, move to home improvement during those months.

The key is matching the category to where your discretionary spending actually goes. If you pick a category you rarely use, you're leaving cash back on the table. Spend a few minutes at the start of each month reviewing your last month's statement and picking the category that will earn you the most in the month ahead.

What happens if you don't choose

American Express assigns a default category automatically if you don't make a choice. This is usually a broad category like "other purchases" or a specific one like "dining," depending on the card. You still earn cash back — you're not penalized for not choosing — but you may not earn the rate that would benefit you most.

Check your account to see what the default is, and if it doesn't match your spending, log in and change it. This is a one-time setup that takes two minutes and can add up to real money over a year.

Frequently Asked Questions

Can I earn the higher rate on multiple categories at once?

No. Custom Cash lets you pick one category per month to earn the bonus rate. All other categories earn the base rate. If you need to earn bonus rates on multiple categories simultaneously, you would need a different card or to carry multiple cards.

What if I change my category mid-month?

The new category takes effect when ready for purchases made after you change it. Purchases made before the change earn the rate that was active at the time. So if you spent $300 on gas before switching to dining, that $300 earns the old rate, and dining purchases after the switch earn the new rate.

Do I have to use the category I choose?

No. You can choose a category and then not spend anything in it that month. You'll earn the base rate on all your purchases. But if you do spend in that category, you'll earn the higher rate on those purchases, so there's no downside to choosing strategically.

Can I see how much cash back I've earned in each category?

Yes. Your American Express account shows a breakdown of cash back earned by category and by month. This helps you see whether your chosen category is actually where your spending is happening, or whether you should switch to a different one.

What if my favorite category isn't on the list?

You can't add it. The category list is fixed by American Express. If your top spending category isn't available, choose the closest match from the available options, or consider whether a different American Express card might offer categories that fit your spending better.