The 31-year-old spent the first half of the campaign on loan at League One side Wigan and will now continue in the third tier with Bradford.
Meanwhile, Championship play-off hopefuls Wrexham, who strengthened their attack over the summer, are gradually seeing members of their promotion-winning squad depart, as the club adapts to the demands of a highly competitive season.
“Wrexham AFC can confirm striker Paul Mullin has signed on loan for Bradford City until the end of the 2025/26 season,” Wrexham wrote on their website.
“Back-to-back-to-back promotion winner Mullin, 31, started the season on loan with Wigan Athletic – scoring five goals. He returned to the Club in January, and will now spend the remainder of the season with Graham Alexander’s Bantams – who currently sit in the play-off places in League One.
“Manager Phil Parkinson said: ‘We're really pleased for Paul, it’s a good opportunity to part of a team challenging at the top of the league.’
“All at Wrexham AFC would like to wish Mulls and Bradford the best of luck for the remainder of the season.”