The following is a list of the ladybird species that I have seen in the UK.
01 7-spot c.1975 Umberleigh, Devon 1
02 2-spot c.1984 Hatfield, Herts 1
03 22-spot c.1987 St. Albans, Herts 1
04 Orange 01/04/1999 West Putford, Devon 1
05 14-spot 04/05/2000 West Putford, Devon 1
06 Harlequin 30/10/2006 Nazeing, Essex 1
07 Kidney-spot 18/09/2008 Broxbourne, Herts 1
08 Pine 15/05/2009 Chingford, Essex 1
09 Epaulet 24/03/2010 Broxbourne, Herts 1
10 16-spot 04/05/2010 Upshire, Essex 1
11 10-spot 10/05/2010 Sawbridgeworth, Herts 1
12 24-spot 20/07/2010 Upshire, Essex 1
13 Red-flanked 20/08/2010 Chingford, Essex 1
14 Cream-spot 08/09/2010 Broxbourne, Herts 1
15 Meadow 22/09/2010 Chingford, Essex 1
16 Adonis 11/10/2010 Nazeing, Essex 1
17 Conifer 07/05/2012 Fishers Green, Essex 1
18 Water 10/05/2012 Fishers Green, Essex 1
19 Red Marsh 10/05/2012 Fishers Green, Essex 1
20 Larch 29/05/2012 Upshire, Essex 1
21 Cream-streaked 30/05/2012 Thundridge, Essex 1
22 Eyed 17/06/2012 Upshire, Essex 1
23 Spotted Marsh 18/06/2012 Fishers Green, Essex 1
24 Bryony 09/09/2012 RSPB Rainham, Essex 1
25 Ivy 12/09/2012 Broxbourne, Herts 1
26 Heather 13/03/2013 Nazeing, Essex 2
27 Red-headed 27/03/2013 Nazeing, Essex 1
28 Dot 19/09/2013 Nazeing, Essex 1
29 11-spot 14/05/2014 Cudmore Grove CP, Essex 2
30 18-spot 15/08/2014 Church Hill, Herts 2
31 Oak 28/06/2015 Fishers Green, Essex 5
32 Scarce 7-spot 22/08/2015 Esher Common, Surrey 5
33 Striped 22/08/2015 Esher Common, Surrey 1
34 Heath 22/08/2015 Esher Common, Surrey 1
35 Hieroglyphic 22/08/2015 Chobham Common, Surrey 1
36 Red-rumped 25/06/2017 Warren Hill, Suffolk 1
37 Angle-spot 03/07/2017 Fen Drayton, Cambs 1
38 Red-patched 03/08/2017 Nazeing, Essex 1
39 Ant-nest 03/08/2017 May Day Farm, Norfolk 1
40 Forestier's 16/08/2017 Nazeing, Essex 1
41 Dusky 15/07/2018 Waltham Abbey, Essex 1
42 False-spot 22/07/2018 Canvey Wick, Essex 1
43 Black 06/09/2018 Thetford Warren, Norfolk 1
44 Horseshoe 07/10/2019 Fishers Green, Essex 1
45 Schmidt's 19/08/2022 Ramparts Field, Suffolk 1
46 5-spot 11/09/2022 Abergavenny, Monmothshire 1
If recording ladybirds in the SE of England then 30 species is an achievable target.
Forty species requires a bit more effort, including travelling to find specific target species.
I have yet to see 13-spot Ladybird (two unsuccessful trips to Sussex).
Whilst I have seen a probable Bordered Ladybird, I am still waiting to see a classic individual that is unambiguous, this species is the most elusive of the resident species.
These are my last two remaining resident species and would take my list up to 48.
Mealybug Ladybird is on the British List, but the only populations are in glasshouses containing tropical butterflies or botanical collections, whether these are tickable is a matter of personal choice.
The status and distribution of Sea-lavender Ladybird is currently uncertain, it may prove to be a resident species.
At the moment it seems that a total of 50 species is just out of reach.
However, as more people search for ladybirds, especially in bird migration hotspots and urban habitats, it is quite likely that more newly established species will be found, either as natural migrants or human introductions.