If you share care of your child with someone you do not live with, that child (under 18 years old) can move between both homes. Therefore, in cases where parents are separated, their child/children can spend time with both parents in both homes and should continue to do so where it is safe.
However, before deciding whether a child should spend time in both homes you should consider:
The government guidance states that, where the child is 13 years old or under, parents are able to form a 'childcare bubble' with one other household for the purposes of informal childcare. This means that someone in one household can provide informal (unpaid and unregistered) childcare to a child or children aged 13 years or under in another household. Importantly, the 'childcare bubble' is restricted to be between two households.
This means that family and friends who do not live in your household and are not part of your support or childcare bubble must not visit your home (or you visit theirs) to help with childcare.
Therefore, grandparents are able to see their grandchildren if they are providing childcare and the same grandparents care for the same grandchildren every time. However, government guidance states that you are not allowed to swap households in your childcare bubble, so grandparents who have more than one set of grandchildren, living in more than one other household, are only allowed to provide childcare for one set of their grandchildren. The 'rule of six' remains in place so your childcare bubble cannot made up of more than six people (including the children).
The guidance states that if you’re a single-adult household, you can form a 'support bubble' (a close support network) with another household, other than the one that includes your child’s other parent.
If you’re not a single-adult household, you can form a 'support bubble' with a single-adult household, other than the one that includes your child’s other parent.
Once you make a 'support bubble' you should not change who is in your bubble.