ASOS – 20% off your purchase. Promo code HISUMMER. Sale ends May 31. I just ordered a bunch from here, they have a great selection of fun summer dresses!
Soma – No actual promo code, but a TON of items on sale up to 50% off just for the holiday. While supplies last.
Swimsuits for All – Free upgrade to 3-day shipping and up to 60% off merchandise. Promo code 16MDW5. No notification on the site when this promotion ends.
Dress Barn – Buy one, get one 50% off shorts, tees and tanks; same deal for dresses in the colors red, white, and blue. Promo code SHOPFORMDW. Sale ends June 1.
Bare Necessities – No actual promo code, but they’re having a semi-annual sale with swimsuits up to 30% off and clearance up to 70% off. Also if you haven’t already, if you sign up for their emails you’ll get a code for 15% off your purchase.