The 19-year-old singer used to work at W Mandeville bakery in his hometown at 6-pounds-an-hour Saturday job when he was 14, reported Daily Mirror.
The customers were shocked to find the boyband star behind the counter.
"It was funny as there were security and chauffeurs and minders outside, and there Harry was acting like he was still a baker's boy earning what he earns in a second now. He posed for fans. He was just lovely," said a source.
Style had left the job two years later when he shot to fame on 'The X Factor'.
"He was the most polite member of staff we've ever had. Customers really took a shine to him. The shop suddenly had an influx of girls when Harry worked here. Sometimes there would be 12 of them pouring in at one time. Even now, a group of 20 girls will sometimes come in and start taking photos of the shop," his former boss Simon Wakefield said.
"He was a really hard worker. His jobs were serving in the shop, cleaning the back, scrubbing the floor, washing the trays and cleaning the counter. Mopping the floor was his worst job, but I never heard him moan about it," he added.