PA MediaThe majority of teachers in Northern Ireland are to hold a half-day strike on Tuesday 21 February.
The UTU and INTO unions are to take action from midnight until 12:00 GMT.
BBC News NI understands that the NASUWT union will also take similar strike action.
It is expected many schools will close until midday, as most teachers in Northern Ireland are represented by those three unions.
The NEU in Northern Ireland is also balloting its members on strike action.
The position of the NAHT union – which represents many school leaders – is yet to be confirmed, but its members have previously voted for a walkout.
Union members are already taking co-ordinated action short of strike in Northern Ireland’s schools.
Some teachers in England and Wales are set to begin strike action on 1 February.
A 16-day wave of rolling teachers strikes is also currently taking place in Scotland.
Stalemate over pay
Teachers there want a 10% uplift in pay, which ministers and councils have said is unaffordable.
They have offered 5% which includes rises of up to 6.85% for the lowest-paid staff.
There has been stalemate over a pay deal in Northern Ireland for teachers for almost a year.
In February 2022 unions rejected a pay offer from employers for the years 2021-2023 as “inadequate”.
The teaching employers claimed the deal was a 3.2% increase over two years, but the unions claimed it consisted of a restructure of pay grades which would lead to many teachers getting paid less.
The unions subsequently asked for a “cost of living” pay increase of 6% for 2021-22 and a rise of inflation plus 2% for 2022-23.
Inflation is currently at over 10% in the UK, driven mainly by rises in the cost of food and energy.
The half-day strikes on 21 February will be the first by teachers in Northern Ireland in over five years.
There have been recent warnings of a wider ‘crisis’ in education funding.
The Education Authority, for instance, has said it cannot make £110m of savings in this financial year without cuts to frontline services.
