If manufacturing overhead has been overallocated during the year, it means the jobs have been:

When manufacturing overhead has been overallocated during the year, it indicates that more overhead costs have been applied to jobs than what was actually incurred. This situation means that the total cost assigned to the jobs is higher than the actual expenses associated with them. Consequently, jobs end up being overcosted because the overhead allocated to them exceeds the actual overhead costs.

Overallocated overhead can occur due to various reasons such as estimating overhead rates too high or an unexpected reduction in overhead costs that weren't accounted for. Since the actual costs are lower than what has been allocated, it results in higher per-unit costs for the jobs completed during that period. This can lead to distorted profitability analysis and pricing decisions if not corrected, as products may appear to be less profitable than they actually are.