While there are no national laws banning vaping indoors in the UK, many pubs and venues have implemented their own bans. National pub chains like Wetherspoons and Mitchell & Butlers prohibit vaping inside premises. Vaping is also banned at English Premier League grounds and on most public transportation in the UK except some train systems. The best approach is to check with establishment staff before vaping, as policies can vary by location.

1. The Laws Of Vaping In
Pubs UKMost people in the UK will remember when a walk to the pub and
suddenly, smoking went on. Since the ban on smoking, those days
have passed.
However, the advent of e-cigarettes has now complicated matters and
resulted in a lot of trouble about whether or not anybody can vape in the
pub. As with a lot of questions of this type, there is no clear answer.
However, it’s best for
you to assume that vaping isn't permitted and to ask the staff if
further clarification is required.
At the moment, e-cigs aren't covered by the legislation that bans users
from smoking indoors. Now, this is because smoking needs the
burning of a substance, and nothing burns in an e-cig when the person
is vaping. But, while there are no national laws preventing use,
different venues are permitted to apply their rules at their discretion,
and many do so - always to the detriment of vapers.

2. National pub chains Wetherspoons have implemented a ban on vaping in
pubs in the UK. The Wetherspoons site explains that: “We don't permit
the use of vaporisers or e-cigarettes outside of the areas designated for
smoking on
our premises. This will include external areas and hotel rooms.”
The Mitchell and Butlers website show a similar note: “For the comfort of
our guests, Mitchells and Butlers don't allow the use of e-cigarettes
within our premises. Recognising that the fumes are non-harmful and
vapours this is not known by everyone and can result in confusion for
others. So, to prevent this, we ask that guests don't use e-cigs on our
premises.”
Also, vaping seems to be banned at all English Premier League
grounds, though how heartily the enforcement of this ban is a
different question entirely.
The enclosed spaces which come with any public transport were often
going to be a tricky area for vapers. Therefore, vaping is banned on all
train systems in the country except for Southeastern and is prohibited in
the London underground too. All airports as well as major United
Kingdom airlines have a full ban on vaping, even though you're allowed
to take the equipment on many planes. Now, Heathrow terminal 4 has a
dedicated vaping section for people who are aching to puff on their
favourite vaping liquid.

3. Enterprise is a leased as well as a tenanted pub company that means
their venues are given to personal operators. It's these operators who
operate every part of the venue, instead of Enterprise, and ao decisions
like use or non-use of electric cigarettes are left to those people. It
implies that while an Enterprise pub may permit vaping, another may
not.
The best thing is to ask any staff at the establishment – and that also
applies for any pub which does not have any clear rule. Where vaping in
some public places are concerned, it is best to play it safe and have
confirmation before you use your device.
Finally, your place of business is your premises, and you have the right of
withdrawing your permission for some to enter the premises given it's on
non- discriminatory grounds. But, if they refuse to leave or try to access,
they commit a trespass.