Simply Be is a company from the United Kingdom. They have oodles of sale pages. I was blown away by the number of dresses on sale. I believe there were around 650 different ones. Not every dress posted is available in every size. (BTW their sizes run from size 8 to 28.) You can search by size so that you can find the dresses that are available in your size. Dresses on their site fall into the following categories: party dresses, maxi dresses, evening dresses, work dresses, swing dresses, and wedding dresses. The prices are pretty good, too! They even have a section for weddings which includes dresses for bridesmaids, mothers of the bride, and guests. Here are just three of the dresses that are currently on sale.
In addition to dresses, Simply Be also sells tops, denim, slacks, t-shirts, skirts, swimwear, shorts, jumpsuits and rompers, shoes, nightwear, and accessories. The variety for each category is extensive. Just a note about the shoe section...The shoes and boots come in three widths, D, E, and EEE. That is important to know because some plus-size sites only carry shoes that are D width.
If you become a VIP for Simply Be you can take 15% off your first order. That means applying for a Be card and using it on your first order. There are plenty of perks that go along with being a VIP. You will receive $20 off your second order if you spend over $100, you will get a special gift on your birthday, you'll have early access to sales, in addition you will get special offers and discounts that are exclusive to all Be card members. Another perk is the ability to earn up to $50 in vouchers each month. Check out this page about the Be card.