Shops no longer in existence

Bodgers of Ilford (a department store)

Supermarkets - Kwiksave, Finefare, Caters, Presto and Safeway.

David Morgan in Cardiff

Civil Service Stores in the Strand

Station bookshops

Little shop in Hale where the lady in the window was mending nylon stockings.....

C & A

Lilley & Skinner

Adams (children's clothes)

Goldberg's

Habitat. I know it's still going, technically, but it's not the same.

Lewis's

Costers ( also a dept store)

Brown And Muffs ( yes it was a real dept store!)

Ahem! some of these are still online shops and at least one of these (Budgens) is still going strong as an actual shop.
I think it may be the case that some have closed in certain areas.

Galbraiths

Fine Fare

Tie Rack

Ottakar's

Liptons

Mansfield’s shoe shop

Budgens

My little sweetshop I used to visit as a child.

East

"The Bourne from which no Hollingsworth returns", as well as Debenham and Freebody, Marshall and Snelgrove, Barkers, Derry and Toms and, I think slightly more up to date, Biba.