New update - with the registrations for the Volvo B8R/Elites and the first of the long E200MMCs

Alexander Dennis Enviro400MMC Euro6
10431-10442 (SK15 HCN/O/P/U/X/Y/Z, HDA/C/D/E/F): Oxford
10443-10451 (SN65 NYY/Z, NZA/B/C/D/E/F/G): Wigan
10452-10456: Exeter
10457-10487: Manchester Hyde Road

Scania N230UD Alexander Dennis Enviro400 Euro5
15211-15220 (YN15 KHH/J/K/L/M/U/R/O/?/?): Fenstanton (Guideway)
15221-15225 (YN65 XFB/C/D/E/F): Lillyhall (GOLD Spec)
15226-15249 (YN65 XEA/B/C/D/E/F/G/H/J/K/L/M/O/P/Q/R/S/T/U/V/W/X/Y/Z, XFA): Chorley (GOLD Spec)
15250: Torquay (GOLD Spec)
15251-15260: Exeter (GOLD Spec)

Scania N230UD Alexander Dennis Enviro400MMC Euro6
15261-15290: Herne Bay

Volvo B8RLE/Wrightbus Eclipse Urban 3
21301-21310: Fenstanton (Guideway)

Alexander Dennis Enviro200MMC 11.8M Euro6
26001-26019 (YX65 PZA/B/C/D/E/F/G/H/J/K/L/M/N/O/P/R/S/T/U): Dunfermline 
26020-26023: Barnsley
26024-26033: Rawmarsh

Alexander Dennis Enviro300 Euro5
27211-27228 (SK15 HBJ/L/N/O/P/U/X/Y/Z, HCA/B/C/D/F/G/H/J/L): Glasgow (Euro6)
27229-27237 (SK15 HFR/S/T/U/V/W/X/Y/Z): Wigan
27238-27240 (SN65 OBY/z, OCA): Stockton
27241-27254 (SN65 OCB/C/D/E/F/G/H/J/K/L/M/O/P/R): Stockton (Connecting the Dots)
27255-27272 (SN65 OCS/U/V/W/X/Y/Z, ODA/B/C/E/F/G/H/J/K/L/M): Birkenhead Rock Ferry (GOLD Spec)
27273-27286 (SN65 ODP/R/S/T/U/V/W/X/Y, OEA/B/C/D/E/F): Cwmbran (GOLD Spec)
27287-27299: Liverpool Gillmoss

Scania K230UB Alexander Dennis Enviro300
28721-28741 (YN15 KFO/R/T/U/P/V/W/X/Y/Z, KGA/E/F/G/J/K/O/P/U/V/X): Cwmbran
28742-28746 (YM15 FPL/N/O/P/T): Banbury (GOLD Spec)
28747-28748 (YN65 XFY/Z): Lillyhall (GOLD Spec)

Alexander Dennis Enviro200 Euro5
37301-37319 (SK15 HDG/H/J/L/N, HEV, HFA/B/C/D/E/F/G/H/J/L/M/N/O): South Shields
37320-37326 (YY15 OWG/H/J/K/N/O/P): Gloucester
37327 (YY15 OWR): Hastings

Alexander Dennis Enviro200MMC Euro6
37401-37405 (YX65 PXS/T/U/V/W): Oxford
37406-37423 (YX65 PXY/Z, PYA/B/D/F/G/H/J/L/O/P/S/T/V/W/Y/Z): Winchester 'The King's City'

Optare Solo SR Euro6
47941-47943 (YJ15 ACV/EP/CX): Carlisle (Blue 60)
47944-47948 (YJ15 AEU/V/W/X/Y): Carlisle (Pink 61/61A)
47949-47953 (YJ15 AEZ/FA/EB/C/D): Carlisle (Purple 62/62A)
47954-47957 (YJ15 AEE/F/G/K): Carlisle (Orange 76)
47958-47966 (YJ15 AEL/M/N/O/T/CY/Z, ADO/U): Carlisle (Rainbow Generic)
47967-47980 (YJ65 ETR/T/U/V/X, ERZ, ESF/G/N/O/U/V/Y, ETA): Leamington (GOLD Spec)

Optare Solo SLR Euro6
48001-48002 (YJ15 ANF/MW): Carlisle (Honister spec)
48003-48025 (YJ15 ADV/X/Z, AEA, ABF/K/N/O/U/X/Z, ACF/O/U, AAE/F/K/N): Exeter
48021-48025 (YJ15AAZ, ANP/R/U/V): Kings Lynn

Volvo B8R/Plaxton Elite Euro6
53801-53812 (YY65 SXH/J/K/L/M/N/O/P/R/S/T/U): Aberhill

Volvo B11R/Plaxton Elite I Euro6
54241-54257 (YX65 ZJZ, ZKB/C/D/E/F/GH/J/K/L/N/O/P/R/S/T): Buchan
54258-54262: Glasgow
54263-54276: Rugby Megabus
55021-55028: Rugby Megabus (Left Hand Drive)

Van Hool Astromega TDX27 Euro6
56028-56050 (EZ 160-182 SZ): Megabus Italy Milan

Volvo B5LH/Alexander Dennis Enviro400MMC Euro6 London
13061-13081 (BG15 KGK/N/P/U/V/X/Y/Z, KHB/C/D/G/H/J, TVZ, TWA, KHA, TWC, KGJ/O, KHE): Plumstead

Alexander Dennis Enviro200MMC Euro6 London
36601-36608 (YY15 OWU/V/W/X/Z, OXA/B/C): Romford

Alexander Dennis Enviro400H Euro6 London
12364-12389 (SN15 LRJ): Plumstead

Alexander Dennis Enviro400MMC Euro6 London
10301-10307 (YY15 OYS/T/U/V/W/X/Y): Romford