Shoppers in Wales will pay 5p per carrier bag they use from October 2011, instead of the original plan for 7p from next spring.
The Assembly Government had initially suggested the higher charge from the earlier date.
Environment Minister Jane Davidson said the lower charge would still change behaviour, and delaying the levy would give retailers longer to prepare.
The CBI said the amendments "struck the right balance" for Wales.
The new charges were announced as the regulations needed to allow Wales' carrier bag charge to become law were laid at the assembly.
The assembly government consulted during the summer on the detail of the charge.
Mrs Davidson said: "We have listened to the feedback we have received from businesses, organisations and individuals from across Wales and beyond and have taken on board the issues raised.
"As a result we are proposing a 5p minimum charge for carrier bags - an amount that I am satisfied will bring about the desired behaviour change without presenting an unnecessary financial burden on the shopper, or preventing impulse shopping.
"We have delayed the introduction to accommodate the needs of businesses and are confident that the October start will allow for a smoother and more successful introduction and will allow retailers more time to prepare.
The assembly government said it was estimated shoppers in Wales took home an estimated 350m carrier bags from the major supermarkets last year - 273 bags per household.
"The charge is aimed at helping us to dramatically reduce our use of carrier bags and encouraging all of us to move away from some of the wasteful and throwaway habits we have developed," added Mrs Davidson.
"It will affect everyone in Wales so it is really important that we get the detail right."
The regulations are due to be considered by the assembly on 30 November.
The CBI said the 5p charge set the right balance between reducing use and not penalising low-income households.
Wales director David Rosser said: 'The extra seven months will give retailers additional time to train staff and ensure IT equipment can process the charge.
"The delay will also give consumer more time to prepare for the charge."
But he said there was concern about restaurants and take-away food outlets as many of these businesses were unaware of they would be affected.