If you’re a small business owner with select American Express cards, you may have heard of Pay Over Time, which lets you opt in to carry a balance on eligible purchases of $100 or more with interest.

This benefit is meant to provide more payment flexibility, and soon new and existing American Express Green, Gold and Platinum business card members will be auto-enrolled for the feature. Auto-enrollment will take place at the start of their November billing cycles.

While Amex is traditionally known for their pay-in-full charge card model, the company is making adjustments to their card lineup to accommodate the changing needs of business owners.

“We’ve long heard from our card members who are small business owners that increased payment flexibility is important to them. This is especially critical during these times of uncertainty,” Brett Sussman, Vice President of global commercial card lending at American Express, said in a press release.

American Express has seen 55% of existing business card members choose to enroll in Pay Over Time, predominately to increase inventory for busy seasons, buy in bulk for a discount or help with cash flow.

How Pay Over Time works

Pay Over Time is a buy now, pay later feature that applies to purchases of $100 or more. Amex states that annual fees, cash advances, including cash and other cash equivalents, certain insurance premiums and any other fees owed to American Express are not eligible for Pay Over Time.

Purchases that are added to Pay Over Time incur interest beginning on the date you make the transaction. (Refer to your card member agreement or online account for the APR.) However, you can avoid interest by paying your Total New Balance in full by your payment due date.

While your card has no preset spending limit, there is a Pay Over Time limit that acts like a traditional credit limit. (You’ll find your limit in your card member agreement or online account.) You won’t be able to carry any balances exceeding your Pay Over Time limit.

New and existing card members will be auto-enrolled in Pay Over Time starting in November, but you can turn the feature on and off as needed.

Bottom line

If you’re a small business owner with a Green, Gold or Platinum Amex business card and occasionally carry a balance from month-to-month, Pay Over Time can be a helpful way to receive more flexibility with your payments. However, if you regularly carry a balance, you should consider using a business card that offers a promotional 0% APR.

The Blue Business Cash™ Card from American Express and the Blue Business® Plus Credit Card from American Express both provide an introductory 0% APR for the first 12 months on purchases (then 13.24% to 19.24% variable APR). Either of these cards are a great way to finance business expenses over your first year as a card member without incurring interest.

Amex business cards typically require an excellent credit score to qualify. When applying, you may need to enter your employer identification number (EIN) and/or social security number (SSN).

Business Green Rewards Card from American Express

Business Green Rewards Card from American Express

Information about the Business Green Rewards Card from American Express has been collected independently by CNBC and has not been reviewed or provided by the issuer of the card prior to publication.

  • Rewards

    2X Membership Rewards® points for each dollar you spend on eligible purchases at amextravel.com and 1X Membership Rewards® for each dollar you spend on eligible purchases

  • Welcome bonus

    15,000 Membership Rewards® points after you spend $3,000 on eligible purchases within the first 3 months from account opening

  • Annual fee

    $0 intro annual fee for the first year, then $95

  • Intro APR

  • Regular APR

  • Balance transfer fee

  • Foreign transaction fee

    2.7% of each transaction after conversion to US dollars

  • Credit needed

The American Express® Business Gold Card

The American Express® Business Gold Card

On American Express’s secure site

  • Rewards

    Get more rewards with 4X Membership Rewards® points on two select categories where you spend the most each month; Get 25% points back, after you book a flight using Pay with Points

  • Welcome bonus

    Earn 35,000 Membership Rewards points after you spend $5,000 on eligible purchases with the Business Gold Card within the first three months of Card Membership

  • Annual fee

  • Intro APR

  • Regular APR

  • Balance transfer fee

  • Foreign transaction fee

  • Credit needed

The Business Platinum Card® from American Express

The Business Platinum Card® from American Express

On American Express’s secure site

  • Rewards

    Earn 5X Membership Rewards® points on flights and prepaid hotels on amextravel.com; 35% Airline Bonus: Use Membership Rewards® Pay with Points for all or part of a flight with your selected qualifying airline, and you can get 35% of the points back, up to 500,000 bonus points per calendar year when you book on amextravel.com

  • Welcome bonus

    Earn 75,000 Membership Rewards® points after you spend $15,000 on qualifying purchases within your first 3 months of Card Membership

  • Annual fee

  • Intro APR

  • Regular APR

  • Balance transfer fee

  • Foreign transaction fee

  • Credit needed

For rates and fees of the Business Green Rewards Card from American Express, click here.

For rates and fees of the American Express® Business Gold Card, click here.

For rates and fees of the The Business Platinum Card® from American Express, click here.

For rates and fees of the Blue Business Cash™ Card from American Express, click here.

For rates and fees of the Blue Business® Plus Credit Card from American Express, click here.

Correction: Annual fee charges are ineligible for Pay Over Time for business cards. An earlier version stated that Pay Over Time applies to your business card’s annual fee.

Editorial Note: Opinions, analyses, reviews or recommendations expressed in this article are those of the CNBC Select editorial staff’s alone, and have not been reviewed, approved or otherwise endorsed by any third party.