Among the manufacturers pledging help during the week (June 1-6) are: Coca-Cola Enterprises (CCE); Imperial Tobacco; JTI; Tetley; Tate & Lyle; McVitie's; Scottish & Newcastle; Coors; Heinz; Britvic; Cadbury; and Dairy Crest.
CCE is offering independents a discounted deal on Fanta, Sprite and Dr Pepper and sending 400 members of its staff to spend a day in a participating store.
Head of communications Edmund Knight said: "Independents play an extremely important role in UK retailing, working long hours to serve their community. We fully support this great initiative to celebrate independent stores."
Wholesalers who will organise related activities include Bestway and Batleys, Booker, Landmark, Sugro, Makro, Costco, Today's and Parfett's.
Steve Fox, director of retail at Booker, which is giving away free cans of its Euro Shopper energy drink via the NIW coupon offer in The Sun on May 29, said: "I hope all independents will see this as an opportunity to help them increase sales and build awareness of the importance of their stores to the community."
Bestway's Younus Sheikh added: "We're keen to get behind this and prove to the customer the value of their local store, now more than ever in these difficult trading times."
Alan Toft of the FWD's My Shop is Your Shop campaign, which organises NIW, said that data from 15,000 shops showed an average 15.7% sales increase on promoted products last year.
"Every independent can use NIW to engage with the community and drive footfall," he added.