In 1941 Holy Trinity merged with the parish of St Mary, Britannia Walk N1 after the latter was made unusable by WW2 aerial bombing.

[2] In 1896 the lowest portion of the tower was converted to a baptistry opening into the south-west corner of the church, to the design of Spencer W Grant (1879–1914).

[2] Following WW2 aerial bombing in January 1941 that damaged the building the chancel area was reordered in 1942 under the supervision of Martin Travers (1886–1948), as follows:[2] At the time Holy Trinity suffered aerial-bomb damage, and by the same air-raid, the church of St Mary, Britannia Walk, Hoxton, was made entirely derelict.

The previous organ by Bishop & Starr was located in the south chancel and removed following WW2 bomb damage.

One apparently noteworthy provision was a drinking-fountain that was accessible to the public as well as the children, "and in that crowded neighbourhood it is hoped will prove a great boon."