Yes – assuming they are adults, and provided the salaries, and any other benefits you pay them, are commercially justifiable.
These benefits could include:
- A company car
- Medical insurance
- Making payments into a registered pension scheme
However, HMRC may consider the overall package excessive, when they take into account the value of the work done by your son and daughter. They could possibly “disallow” some of the payments – then your business will not get tax relief on all of the costs – which would be bad news.
So, ensure their pay is the market rate for what they do in order to justify their pay. You should also make sure that they receive and sign a formal contract of employment.