5 CFR 1620.14: Payment to the TSP record keeper.

(a) The employing authority of a cooperative extension service employee (described at § 1620.11(a)) is responsible for transmitting employer and employee contributions to the TSP record keeper.

(b) The employing authority of a union employee or an Intergovernmental Personnel Act employee (described at § 1620.11(b) and (c), respectively) is responsible for transmitting employer and employee contributions to the employee's Federal agency of record. Employee contributions will be deducted from the employee's actual pay. The employee's agency of record is responsible for transmitting the employer and employee's contributions to the TSP record keeper in accordance with its procedures. The employee's election form (TSP-1) will be filed in the employee's official personnel folder or other similar file maintained by the employing authority.