There are limited trains with first class within Scotland - many trains do not have first class. Please check before buying a ticket that your train will convey first class carriages. There is no first class on any West/North Highland route.
The London & North Eastern Railway operates trains from England into Edinburgh, then some of them continue onto Glasgow (20:17 Mon-Friday), Inverness (1633 daily) and to Aberdeen (1028, 1429, 1832, 2032 weekdays, no 2032 on Saturdays. Sundays 0910, 1428, 1836) These trains have an enhanced first class product of 2 carriages per train with complimentary food and drink offers on all services. This includes a hot option on weekdays. Alcoholic drinks are included weekdays also . (*** Limited hot option and no alcohol during pandemic period ***) Spacious seats in formations of 4 around a table, 2 over a table - restaurant style, and some single seats too. If you can afford it - you are unlikely to be disappointed on these trains, Times out of Inverness - 0755 Mon-Sat, and 0940 Sundays. Out of Aberdeen - 0752, 0952, 1452 Mon-Sat, plus 1818 weekdays. Sundays - 0949/1149/1349 approximately. Check the menu rotation here
Cross Country trains.operate every two hours between Edinburgh and Glasgow Central via Motherwell, and can provide space and comfort on this sector. Much more comfortable seats than on the Scotrail commuter trains on the Edinburgh to Glasgow Queen Street route in first class. Usually Cross Country does not offer any refreshments on this sector, not even a glass of water, beware. On rare occasions you will find this service, but usually it only comes onboard between Edinburgh and England, via the East Coast Mainline via Berwick upon Tweed .
Trans Pennine operate services every few hours from Glasgow Central, and every 2 hours from Edinburgh to Carlisle (most, but not all stop at Lockerbie) and onto the lake district and Manchester Airport. They have the middle third of a carriage blocked for first class - quite comfortable, on these electric trains that are only a few years old. The trolley attendant offers cold snack options like cake, crisps, sandwiches, and hot and cold drinks included in your fare.
All trains from Glasgow and Edinburgh to Lockerbie and Carlisle on the border, (and beyond to Birmingham & London Euston) operated by Avanti West Coast, carry first class. The picture to the left is of Avanti's very nice first class - with complimentary meal or snack and drink inclusive pricing. If you can afford it - do so. There are 3 or 4 carriages per Pendolino train, and one carriage on the shorter Voyager trains. Hot food options are available on weekdays, as are alcoholic drinks. (*** A reduced catering offer during the pandemic)
Scotrail (picture to the right) offer first class on most services fropm Glasgow and Edinburgh to Inverness and Aberdeen. This is their current product, however you may get to travel on their new (refurbished Great Western trains) larger trains, offering a whole carriage of first class, with catering included. Currently, you might get a tea or coffee in a plastic cup, and a shortbread or similar - not overly worth it for such a price difference. You still have to walk through standard class to the toilet. Scotrail have ultra new fast electric trains operating on the Edinburgh to Glasgow via Falkirk High route which offer a small first class section, and if the trolley reaches you on the journey, a drink and small snack is offered. .*** Catering suspended during the pandemic times ***
