Principals have been told they should only close schools to pupils as a last resort when many teachers strike in Northern Ireland.
The guidance came in a letter to school heads from the education management bodies.
It also advises heads to organise remote learning for pupils if their school has to close.
Teachers in three big unions - the NASUWT, INTO and UTU - are due to hold a half day strike on 21 February.
The action, from midnight to 12:00 GMT, is due to continuing stalemate over a pay deal.
