Sensible post Discount, in part you almost sound like the accountant.
I won’t go into detail, “reasonable” and “records” are important and it won’t matter if the accounts are looked at. As everything is above board and permitted.
It’s your business, think for yourself and don’t listen to scare tactics and misunderstood advice.

Ewan, you need to go into detail to get the correct answer!
The whole point is
DETAILIf you're just generally wondering whether other window cleaners claim meal allowances then I suspect some would quite rightly say yes, and some would say no.
Its the
DETAIL that matters when speaking to, or dealing with HMRC
Case 1:
Guy lives in Birmingham and travels to London for 2 days work. He stays in a hotel and claims an allowance for meals.
Case 2:
Guy lives in Birmingham and spends his 8 hours working in and around the town. He returns home at 5pm
Do you see how different rules will apply to each case?
If not, why not claim the price of a Travel Lodge each and every day you sleep at home as well?
You have this strange habit of keeping things a 'bit of a mystery' when presented with differing views.
As I have already clearly stated, if your round is 'local' (and yes, I did give you a clear definition of my interpretation) then you're on to a loser.
If on the other hand, you work away regularly then it would be an acceptable expense (for the days you worked away).
If you spoke to your accountant in the vague manner you have shown on this discussion, then I am not surprised you have been led up a blind alley.
So what position are we talking about
EXACTLY Ewan? working away and claiming meal or 'local' and claiming meals?
The answer to this question will have an impact on the advice you will receive from an accountant.
...and yes, I do use a firm of chartered accountants and yes, I have discussed (at length) this very subject.....and still managed to fall foul of HMRC!!