Open Addresses UK
Open Addresses UK is a repository/aggregated dataset for United Kingdom addresses data supposed to launch in 2015 (see https://web.archive.org/web/20150929075911/https://alpha.openaddressesuk.org/blog/2015/07/27/a-time-for-going-to-bed for partial explanation of failure)
Can we put OpenStreetMap data into Open Addresses UK?
No we can't bulk export OSM data and put it into Open Addresses UK, since they are creating a dataset which has no "sharelike" requirement.
You as an individual mapper can put data into OpenStreetMap and then put that same data into Open Addresses, since you own the intellectual property of map data you have gathered yourself.
We might also aim to persuade a lot of UK address mappers to re-license those contributions. Lots of open questions about how that would work.
In general though OpenStreetMap is not actually of much interest to the Open Addresses UK project as a bulk data source, since we only have a tiny minority of UK addresses. What's more interesting is whether we can be part of a mechanism of community contribution, and also if we can use their data in our map...
Can we put Open Addresses data into OpenStreetMap?
The creators of Open Addresses UK stated that they would hope to see address data put into OpenStreetMap, and the project has adopted an attribution license which should allow this by listing them on the OpenStreetMap Contributors page. However...
This raises lots of questions. More discussion to be had (and decisions documented here)
Please do not begin importing Open Addresses UK data into OpenStreetMap until plans have been discussed by the UK OpenStreetMap community