The M&S guarantee, effective from the purchase date, covers manufacturing and material defects but not normal wear and tear or accidental damage, said the brand.
The guarantee is part of M&S's Another Life initiative, which is aligned with the company's Plan A sustainability strategy.
It emphasises circularity through Rewear, Repair, Recycle, and Resale. The Rewear component aims to assure customers of product durability.
This move builds upon M&S's existing 100-day return policy for back-to-school items. The one-year guarantee promises a full refund within 365 days for the entire kids' clothing range, including school uniforms.
M&S is focusing on kidswear as a growth avenue within its Fashion, Home & Beauty segment, aiming to attract more family shoppers and increase its market share.
Over the past two years, M&S has enhanced its value perception in kidswear by five percentage points while maintaining its reputation for quality.
Earlier this year, the retailer reduced prices on over 100 products by 20% in its 'everyday essentials' kidswear range.
The company also asserts that its kidswear is responsibly sourced with all cotton coming from responsible sources and over 90% of polyester being recycled.
M&S kidswear director Alexandra Dimitriu said: “At M&S, exceptional quality products are at the heart of everything we do. Quality and durability is in our DNA, and is an important part of our Plan A roadmap as we move toward a more circular economy. In Kidswear, our customers have always trusted us for the hand-me-down quality of our clothing, knowing that every single item they buy, whether it is a jogger, a dress or a piece of school uniform, is exceptional quality and trusted value.
“With an authoritative lead in quality, we’re going one step further to give our customers the confidence that any item of kids clothing they purchase, is made well, made to last and can be given another life when their children grow out of it. As a mum myself, I know just how important this is.”
