Marriott Bonvoy cards are split across two issuers with overlapping restrictions, which makes eligibility genuinely hard to work out by hand. Tell the tool which cards you hold and roughly when you opened them, and it narrows down what you can still earn a welcome bonus on.
Marriott Bonvoy is unusual in that its cards are issued by both Chase and American Express, a leftover from the Marriott and Starwood merger. That split is the whole reason eligibility is confusing. The restrictions do not stop at the issuer boundary: holding or recently opening a card from one issuer can block a welcome bonus on the other side. You cannot work out your position by looking at Chase's rules alone, or Amex's alone, which is exactly the gap this tool fills.
For the Chase-issued Marriott cards, the usual 5/24 guidance applies: Chase generally declines applicants who have opened five or more personal cards from any issuer in the past 24 months. You can be perfectly eligible under Marriott's own product rules and still get declined on 5/24 grounds. Run our Chase 5/24 calculator alongside this one so you are not surprised by a hard pull that was never going to succeed.
On the Amex side, the once-per-lifetime language on welcome offers means a card you took a bonus on years ago is usually off the table for good. Amex will normally tell you before you submit whether you are eligible for the offer, which is worth using rather than guessing. Order matters more than people expect here, because taking the easy bonus first can quietly close off a better one later.
Most Marriott cards hand you an annual free night certificate capped at a points value, and for a lot of holders that certificate alone covers the fee. The catch is that Marriott moved to dynamic award pricing, so a certificate that comfortably covered a property a few years ago may no longer reach it. Check what your certificate can actually book before you renew, and see what your balance is worth on our Marriott points calculator.