Roughly 45,000 retail stores could close their doors in the next few years, a new retail report by UBS estimates.

UBS modeled out the share of e-commerce shoppers in the U.S. growing from 21% to 26% and retail growing overall by 4% and said that would lead to mass closures by 2028, Retail Dive reports.

The growth of online shopping, capital constraints, cost of store operations and inflation will drive store count down from 958,000 to 913,000, UBS predicted.

About 1,300 store closures have been announced so far this year, Business Insider reported.

Rents have risen an average of 10% per year for the last three years, well above the historical rate of 3%. If they continue to rise with inflation, physical retailers may not be able to keep up with the costs of operation.

Closures will vary by subsector, with clothing and clothing accessories leading the pack at 17,000, by UBS’ count. The financial services firm also called out department stores, which are losing ground to discount retailers. Some department stores are closing locations already, like Macy's, which plans to slash 150 stores from its footprint this year after filing for Chapter 11 bankruptcy.

Luxury department store Nordstrom, which shut down 15 locations last year, is exploring a take-private deal to stay afloat. In the meantime, it relaunched its website with an enhanced online marketplace in March to attract e-commerce shoppers. It hasn't discussed any intention of closing additional stores.

Due to operational costs and the bankruptcy of clothing brand Express, mall owner Macerich said it has begun executing a plan to sell some assets or hand them over to lenders. The REIT reported a net loss of $126.7M in the first quarter, more than double its $58.7M loss in Q1 2023.

There are about 8.6 malls per million households, as opposed to 10 in 2009 and around eight in 1980. UBS said this is too much space, as the popularity of online retail shopping is reducing the need for physical stores.