To not pay subs?

Do all call centre workers in insurance companies or banks have DBS? After all they have access to financial information Friend of mine has done 30 years in accounts and payroll and never had one

It's not actually legal to ask for an Enhanced DBS if you do not work directly and regularly with children or vulnerable adults (I doubt that Scout leaders would count as vulnerable).
Nevertheless, many organisations will require one for roles where it's not legal to ask for one (e.g. schools where you will be going on one single daytime trip).
For an admin role in Scouting it's a bit of a grey area because you might need the lower level DBS for the financial aspects (with a large group of 100+ kids and £300-400 per year per child for subs, camps etc. that's over £30K turnover per year) (my DH had one of these for his former job in finance), but it could be argued you will be a regular at meetings (even if it's just start/end to pick up financial things) and therefore work with children "regularly".

Because you have access to personal details

And you have to work with the adults. DBS isn't just about kids

Options: (1) volunteer to help so they don’t have gaps & cancellations (2) move to another club.

Pay and keep shtum.
When they cancel due to illness they still have to pay the hire fee for the hall.

You coukd volunteer yourself then there would be fewer cancellations

So do many office jobs that don't require a dbs. Or certainly didn't in 2009

When I was a Cub leader (I moved to Explorers 3 years ago), we worked on 75p per Cub per week.

So why didn't you pay this term's subs in April, as you knew it was £25 for the term ?

I do understand it is frustrating when you are expecting 12 sessions a term, to have 4 missed BUT that is ridiculously cheap, so still very good vfm even if half of them were cancelled.

YABU.

The admin involves financial information and other sensitive information

You couldn’t make every session and that’s ok. But they can’t make every session and that’s not ok?

OP it's £25 per term. I'm cringing for you.

If lose a days pay as if have to take it off work to get to the beavers an hour earlier. And I cant hear on video calls as no subtitles . Besides this was 15 years ago

Yes his sister was 18 at the time

Why would you need one to do admin. Nowhere near the kids.

Just for perspective:
Our unit broke up "early" but we have a trip coming up this weekend which we decided was better for them to have the meeting off beforehand

Getting ready for this trip I have:
Emailed parents to invite them
Booked and paid
Read a pack of information to make sure I have all the details
Creates forms
Sent another email to parents with the forms
Completed a risk assessment
Booked travel after enquiring at a few places for quotes
Sent information to every other leader going
Answered questions off parents which have already been included such as when it is and where it is
Created a home contact list
Brought food and snacks for myself

All before you then consider the day I will give up for said event

And the fact that I work

They might have "missed" 2 sessions but I haven't been slacking off

In theory, the group could pay for the babysitter for a parent to volunteer but I bet the other parents wouldn't want the fees to increase to cover that - even if it meant fewer cancelled sessions.

Not everyone pays for a sitter to have nights out either, surely you can’t think that? Why would your job magically allow it once a month? What if you also help care of a friends kids or an older relative? Weird to assume everyone that can’t volunteer is just unreasonable

Of course there will always be exceptions, I accept that, but I don't believe for a moment that out of 32 cubs families that only about 6 of them can manage to find the time to help out for one session per year! It doesn't have to be a parent that attends - it can be a grandparent, aunt, friend, older sibling (over 18). Very strange how they don't want to help when it's an evening of litter picking, but are available when we go to the dry ski slope. They are way too busy at a weekend to help with a fund-raising tombola because it's family time, but have no such problems when it's help needed on a weekend trip to an airshow.

Believe me, the vast majority (not all) could rearrange their schedule when it suits them, they just don't want to.

I can see both sides. I volunteer at a children's sports club and I'd say that majority, of parents unless they have volunteering experience themselves have little understanding of quite how much time and effort volunteers put into running these things. But thankfully there's only a small minority who have totally unreasonable expectations about what their £3 a week entitles them to.
In my experience most voluntary groups are running on the lowest fees they can manage. But baseline costs have to be paid come what may and unless you're lucky enough to have a sponsor or some other kind of external funding that money has to come from members/parents either directly or via fundraising. It's not reasonable to expect volunteers to cover any losses - it costs many, probably most of us money to volunteer as it is.
There are different ways to do it of course. Our activity is weather dependent and we have to pay the facility hire whether we go ahead or not, so we have to find that money somewhere. We choose not to charge for cancelled sessions but the weekly rate is slightly higher as a result. We know roughly how many weeks get cancelled each year and factor it in. Charging a lower weekly rate but not refunding cancelled sessions would also work but is more likely to annoy parents. The bottom line is that if parents want their children to be able to participate in clubs they do need to cover the costs. If you want refunds for cancelled sessions you'll end up paying in a different way.
However, there are some people who seem to see "But I'm a volunteer" as some kind of get out of jail free card. Being volunteers doesn't absolve you from the responsibility to run your organisation properly and whilst it's completely unreasonable to expect 100% attendance from any volunteer, we do expect ours to be fairly committed and we have asked unreliable people to leave before now, even if that has meant reducing the number of members. I think members should be able to expect that most of the sessions they have signed up for will run barring unforeseen circumstances and I'd say that any group that is having to cancel regularly due to lack of personnel needs to look at whether that group is in fact viable in it's current form.
In the OP's circumstances I'd pay but I would be a bit irked and I'd probably be talking to the organisers about ways to increase the volunteer pool.

Not everyone pays for a sitter to have nights out either, surely you can’t think that? Why would your job magically allow it once a month? What if you also help care of a friends kids or an older relative? Weird to assume everyone that can’t volunteer is just unreasonable.

They shouldn't have asked you to pay for a dbs. We only dbs our regular volunteers, not our occasional ones, and we pay for it. Why would you need to lose a day's pay? DBS check are now done online/video call. Our parent volunteers are for ratio purposes more than anything else, we have to have 1 adult to 5 children if we leave the hut, and with 2 leaders and 24 girls we just can't do it without them. They do have to be over 18 though, was his sister over 18?

We do ask parents for help with the banking/finances (have to submit accounts for audit each year, which is madness), admin bits etc, but no help is forthcoming. We also sometimes do things on weekends, which would think would be much easier for most to help, but nope.

I’m guessing it’s Brownies or similar.
the coat of the venue will be the same for the term, and the sessions are dirt cheap anyway so you should pay up.

Term started in April though, surely? So regardless of missed sessions, not having paid by July is late by anyone's standards.

It sounds like a unit that is struggling, for sure, and YWNBU to either offer to join the leadership team yourself, or have a word with the local commissioner in case they're not aware of the problems. Withholding payments is not going to help anyone.

You should never have to pay for a DBS check and the online stuff can be done at the start of a meeting. I wonder if you have misunderstood?

Volunteer DBS is free.
You need one for the admin side as well.

That's why I suggested upthread offering to volunteer from home/daytimes (doing admin, creating and collecting in forms for camps etc., doing the shopping, prepping crafts) and weekends (organising and taking girls on outings).