| Date | Legislation | Effect |
|---|
| 20 October 1844 | Counties (Detached Parts) Act 1844 | Transferred Icomb and the hamlets of Alstone and Little Washbourne (both in the parish of Overbury) to Gloucestershire
Transferred Broom and Clent from Staffordshire, the townships of Halesowen, Cakemore, Hasbury, Hawne, Hill, Illey, Lapal, Ridgacre, Hunnington, Oldbury and Romsley (all in the parish of Halesowen) from Shropshire and the chapelry of Rochford (in the parish of Tenbury) from Gloucestershire |
| 1 October 1891 | | The Balsall Heath district, which had constituted the most northerly part of the Parish of King's Norton, was added to the County Borough of Birmingham, and for the purposes of the Local Government Act 1888 was thereafter deemed to be in the Administrative County of Warwick. |
|
| 1893 | | Transferred Edvin Loach (a detached part) to Herefordshire |
| 9 November 1909 | | Quinton Urban District was formally removed from Worcestershire and incorporated into the County Borough of Birmingham, and therefore into Warwickshire.[1] |
| 9 November 1911 | LGB Provisional Order 1910 Confirmation (No. 13) Act, 1911 | The Rural District of Yardley and the greater part of the Urban District of King's Norton and Northfield (which included most of Bartley Reservoir) were absorbed into the County Borough of Birmingham, and thereby became part of Warwickshire.[2] |
| 1 April 1931 | Provisional Orders Confirmation (Gloucestershire Warwickshire and Worcestershire) Act, 1931 | The town of Shipston-on-Stour and the parishes of Alderminster, Tidmington and Tredington ceded to Warwickshire.[3]
Redmarley D'Abitot, Staunton, Blockley, Daylesford and Evenlode parishes ceded to Gloucestershire |
| 1 April 1966 | The West Midlands Order, 1965 | The Staffordshire towns of Smethwick and Rowley Regis were added, as components of the newly formed borough of Warley.[4] Dudley was ceded to Staffordshire.[5] |
| 1 April 1974 | Local Government Act 1972 | Halesowen and Stourbridge were ceded to Dudley, which became part of the newly formed West Midlands county, as did Birmingham. The rest of Worcestershire became part of Hereford and Worcester.[6] |
| Interregnum |
| 1 April 1998 | The Hereford and Worcester (Structural, Boundary and Electoral Changes) Order 1996 | Herefordshire and Worcestershire re-established as two separate counties.[7] |