Marts will be allowed operate in counties under Level 4 Covid-19 restrictions according to the Irish Co-Operative Organisation Society, which represents many marts.
Government ministers last night decided to move Donegal, Cavan and Monaghan to Level 4 Covid-19 restrictions for a four-week period from midnight tonight.
ICOS has said that it has agreed the conditions under which sales will continue with the Department of Agriculture.
Buyers only will be allowed attend marts and must maintain 2-metre distance in mart rings.
Those attending must wear masks, no shields or visors will be allowed.
Sellers are being advised that they will not be allowed stay on the mart premises at all, and can only drop animals off for sale.
Those buying animals will not be allowed view the animals in penning areas prior to the sale, as would be normal.
In a communication sent to marts by ICOS, the organisation warns members that if Level 5 is introduced, all mart sales will move to online.
The Department of Agriculture is expected to confirm the measures later today.