The scheme is open for applications. If you want to take advantage of the simplified processes for Internal Market Movements, you should apply as soon as possible.
If you want to use the UKIMS to send B2B parcels from Great Britain to Northern Ireland, you should speak to your parcel carrier and apply as soon as possible.
The process of authorisation will take several weeks so you should apply as soon as possible if you intend to move ‘not at risk’ goods to Northern Ireland imminently, and wish to make use of the simplified processes under the Windsor Framework
You can apply for the UKIMS on GOV.UK