The 4-VEP, later Class 423 750V DC EMU was a mainstay of the Southern Region's outer suburban services from the late 1960s until the early 2000s. They were 90mph 4-car units with an external door to every seating bay, a factor that led to their demise due to safety concerns over slam door stock.
- Class 150
- Class 156
- Class 158, 159
- Class 165, 166
- Class 168 & 170-172
- Class 180
- Class 185
- Class 220, 221, 222
- Class 319, 769
- Class 320, 321, 322
- Class 325
- Class 345
- Class 350
- Class 375, 377, 379, 387
- Class 390
- Class 397
- Class 421 4-CIG
- Class 442
- Class 444, 450
- Class 455, 456
- Class 458
- Class 491 4TC
- Class 701
- Class 707
- Class 800 - 810