There is no legislation specifically related to an employer seeking to recoup training costs; however, contractual arrangements can seek to recover the money you have spent on making sure your staff have the necessary skills to perform their role.
So, unfortunately, if you did not enter into a formal agreement with your employees before they started their training, or did not obtain express agreement from the employee before they left to deduct the monies, then you will not be able to claim back the money you invested in training your employees. However, introducing a policy for new staff will mean that you can do this in future.
Also see: A guide to induction and training
It is doubtful whether the costs of your standard in-house training that is given to new starters would be considered a type of work-related training from which you would seek to recover costs at a later date. The cost of on-the-job training is normally something that you should budget into your normal expenses and is not something you will be able to recover, even though your employees left after just two months, for example.
However, if you paid for more formal, work-related training that your employees chose to undertake, such as training that has enabled them to gain a professional qualification that will prove useful outside of your employment, you may be able to recover some of the costs if you introduced a formal training agreement and the employee signed their agreement to it.
A training agreement is a contract between employer and employee that sets out the terms and conditions for paying for training. This will usually stipulate that the whole or part of the cost of training paid for by the employer will be recoverable should the employee leave within a certain period of time. A sliding scale is usually used which provides for a decreasing payback provision corresponding to the length of service the employee has after the training is completed.