An employee is entitled to return to the same job as before if the parental leave was for an isolated period of four weeks or less.
An employee is also entitled to return to the same job if the period of parental leave was for four weeks or less and followed a period (of any combination of) maternity, adoption, paternity or shared parental leave of 26 weeks or less in respect of the same child. Read more on maternity leave and pay, paternity leave and pay and adoption leave and pay.
If the parental leave period is longer than four weeks, or is preceded or followed by any period (or some combination of) maternity, adoption, paternity or shared parental leave of more than 26 weeks, the employee is entitled to return to the job as before - but only if it's reasonably practicable.
If it is not reasonably practicable for the employee to return to the same job, they are entitled to return to a similar job with the same or better terms and conditions and status as the old job.
An employee returning to work after parental leave is entitled to benefit from any general improvements to the rate of pay (and any other terms and conditions) which you may have introduced for their grade or class of work while they have been away.