| August 1940 | CO: Lt Col JAL Powell |
| Aug 40 | North Irish Horse |
| 2/8/40 | Portrush CO granted leave for period 2nd to 8th Aug and Major D Dawnay assumed command for that period. |
| 5/8/40 | The following three officers attached to this Regt from 12th Royal Lancers:- Lt BMH Shand, Lt GA Smith, Lt MS Barker. |
| 12/8/40 | 2Lt JE Byrne posted to the Regt and joined B Sqn. |
| 19/8/40 | Lt JAO Walker posted from 13/18th Hussars and Lt J Dennistoun posted from 14/20th Hussars. |
| 22/8/40 | FGCM held on 7903556 Tpr C Anderson and 1422954 Tpr D Ferguson on charge under AA 6(2e). |
| 23/8/40 | Sentence of 56 days detention confirmed by Div Cmdr. |
| 27/8/40 | FGCM held on Tpr DG Shanks and Tpr JA McKee on charge under AA 40. |
| 28/8/40 | Sentence of 28 days detention confirmed by Div Cmdr. |
| 30/8/40 | CO addressed all WOs and NCOs. |