Is there any guidance about circumstances/exemptions for employers to not facilitate Shared Parental Leave e.g. efficiency savings/budget cuts?

I presume this question relates to the Work and Families Act (NI) 2015, due to come into operation in April. In short, no. As long as your employee is eligible and has given the correct notice and documentation, you cannot refuse or defer a request for a continuous period of shared parental leave. The right does not operate in the same way as the right to request flexible working where eight business grounds are recognised which employers can rely on when rejecting a request.

However, you can refuse to agree to a request of discontinuous shared parental leave. Even then, your employee has the right to submit up to three separate notices of leave/amendment. So if you do refuse, they could