The Knot has a Newlywed Fund: (The Knot charges one of the lowest fees in the wedding industry at 2.5 percent, they pass this fee directly to the gift-giver with no markup, so the couples keep 100 percent of the gift amount requested and it links right to your bank account.
Honey Fund (Honeyfund encourages guests to send gifts via cash or check directly to you to avoid all fees, though they can pay by credit card through WePay (2.8 percent plus $0.30 fee) or PayPal (2.8% plus $0.30/transaction). https://www.honeyfund.com/ Tendr: (2.7% Credit Card Fee and a $3 transaction fee) https://tendr.com/about/pricing
Travelers Joy (2.95% Credit Card Fee $0.99 at checkout, you or your guests can pay this)
Not recommended for its the highest charge... (If your guest uses a credit card, there's a 2.5% transaction fee deducted from the gift amount. The gift giver is also charged a 2.5% and $0.99 transaction fee on checkout when using a credit card, bringing the fee to a total of 5%)
And/Or you can use Zola, which puts all the items and Funds on one page. Making it easy!