The activation of the defender's 24-recall notice comes on the same day as Cobblers' on-loan winger Stuart Dallas was recalled by parent club Brentford.
Tozer returns to Sixfields in the wake of Aidy Boothroyd's sacking after Saturday's 4-1 home defeat to Wycombe left the club rooted to the foot of the League Two table. Assistant manager Andy King has been placed in temporary charge.
Tozer linked up with Colchester at the end of November and made just one league start, coming in the Essex club's 4-0 home defeat to Notts County.
The 23-year-old was due to remain with the U's until January 4 but will now be back in Northampton's squad for their Boxing Day trip to Burton.