Between massive welcome bonuses and an impressive loyalty program, American Express has some of the best rewards credit cards out there. It’s tempting to stock up on Amex credit cards for the perks and welcome bonuses.

However, there are quite a few restrictions that govern Amex card approvals. Understanding these rules will increase your odds of getting approved for an Amex card and ensure you don’t waste a credit inquiry on a card you don’t qualify for.

It’s not all about creditworthiness in this case. Eligibility is based on whether you’ve received a welcome bonus before, the number of credit card applications you’ve submitted within a specific timeframe and the type of cards you currently have with American Express.

Navigating all these rules can be overwhelming and difficult. But there are so many rewards on the table, familiarizing yourself with them is definitely worth the trouble. We’ve taken the guesswork out of it and done the research. Here’s a complete guide to current Amex application rules.

American Express once-per-lifetime rule

As the name suggests, Amex’s once-per-lifetime rule restricts welcome bonuses to one per card. So if you apply for The Platinum Card® from American Express today and earn the 100,000-point bonus after spending $6,000 within six months, you won’t be eligible for another bonus on that card.

Because of this restriction, you’ll want to apply for the highest welcome bonus possible on an Amex card. A quick Google search can help you figure out whether the current welcome bonus on a card is the highest. You’re only eligible for a welcome bonus once, so you want to get the most points possible.

Which credit cards are affected by the Amex once-per-lifetime rule?

The once-per-lifetime rule applies to all personal, business and charge cards. Contrary to popular belief, charge cards do have a spending limit—it just isn’t pre-set. You may need pre-approval for substantial purchases. In other words, don’t buy a yacht before clearing it with Amex first!

Exceptions to the rule

Where there are rules, there are exceptions. Even though American Express has this once-per-lifetime restriction, people have been targeted for bonuses that exclude this language. If you receive a targeted offer for an Amex card you’ve had before, check the terms and conditions for the following language:

“Welcome offer not available to applicants who have or have had this Card or previous versions of the card. We may also consider the number of American Express Cards you have opened and closed as well as other factors in making a decision on your welcome offer eligibility.”

There are even reports of existing cardholders being targeted for second and third bonuses on the Amex Platinum card. Again, check the terms of the offer for this exclusionary language.

Amex five-card rule

American Express limits all customers to five personal and business credit cards at a time. The five-card rule does not apply to charge cards, which provides some flexibility if you need more than five Amex cards. Charge cards include the Amex Platinum, American Express® Gold Card and American Express® Green Card.

Amex 1-in-5 rule

The 1-in-5 rule limits card approvals to one every five days. If you are applying for multiple Amex cards, simply wait at least six days to ensure you don’t get rejected for that second card. You can apply for two Amex cards in one day—as long as one is a charge card and the other a revolving credit card. Otherwise, you won’t qualify under the 1-in-5 rule.

Amex 2-in-90 rule

American Express restricts card approvals to no more than two within 90 days. You’ll want to coordinate this restriction with the 1-in-5 rule to increase your odds of being approved for multiple Amex cards.

Unfortunately, there are no exceptions to the Amex 2-in-90 rule. Amex has so far enforced this restriction consistently.

How to find out if you’re eligible for an Amex Card before applying

Unsure whether you qualify for an American Express card under any of these rules? There is a simple way to find out before applying: Start filling out an online credit card application. If you’re not eligible for the welcome bonus, you’ll receive a pop-up warning before hitting send.

If you’re ineligible under any Amex application rules, you will know before incurring a 2-5-point hit on your credit score. This is especially significant if you’re going to apply for a Chase credit card down the line. Chase’s 5/24 rule means you won’t get approved for a Chase card if you’ve had five or more credit inquiries over the last 24 months. That goes for credit inquiries at all banks, including American Express.

The best Amex cards to apply for

The best Amex card to apply for depends on your spending habits and reward goals. It comes down to whether you want a personal card, business or co-branded card. Here’s a look at the types of Amex cards available and how to determine which one is a good fit for you:

Personal cards that earn Membership Rewards

If you’re looking for a card with lots of travel benefits, the Amex Platinum card is pretty much unbeatable in this category. It offers tons of statement credits, airport lounge access and a nice welcome bonus: 100,000 Membership Rewards points after you spend $6,000 on purchases on your new card in your first six months of card membership. This bonus is worth about $2,000, depending on how you redeem it.

However, if you want a card that rewards your everyday spending, the Amex Gold card might be a better fit. The card earns 4X points on dining worldwide and U.S. supermarket spending (up to $25,000). These are two substantial spending categories for most people, allowing you to keep earning points long beyond the welcome bonus. Right now, Amex Gold is offering 60,000 Membership Rewards points after you spend $4,000 on purchases in your first six months of card membership. Amex points are worth about two cents each, valuing this card’s bonus at $1,200.

Business cards that earn Membership Rewards

American Express has business versions of most of its popular cards. However, if you want a no-annual-fee business card, The Blue Business® Plus Credit Card from American Express is a great option. The card earns 2X points on the first $50,000 spent every year. It’s great for folks who don’t want to deal with credit card category bonuses, since every purchase earns a flat 2 points per dollar spent.

This card doesn’t always offer a welcome bonus, making the current one worthwhile: 15,000 Membership Rewards points after spending $3,000 in eligible purchases within the first three months.

Co-branded cards

Thanks to a slew of transfer partnerships, Amex cards that earn Membership Rewards are pretty much devaluation-proof. However, Amex also has several co-branded credit cards to choose from. If you’re looking to achieve elite status via credit card spending or annual spending bonuses, then a co-branded card may be a better choice.

The Hilton Honors American Express Aspire Credit Card is a great pick, as it comes with automatic top-tier status. And the Delta cards are great for Delta loyalists who want to accelerate their elite status goals. Amex partners with many popular loyalty programs and chances are, there’s a card that fits your needs.

You may be able to get a higher welcome bonus through Bankrate’s Cardmatch tool, so be sure to check that out before applying through other links.