Grammar

Please provide us with the sentence/s.

The main two places for using the comma before 'and' are:

1. Separating independent clauses:

He rode a bike, and she climbed a tree.

2. Separating items in a list:

He bought an apple, two oranges, a banana, and a bag full of lemons.

In the last case, if you have "a banana and a bag full of lemons" it could be interpreted that the banana and bag are ful

free_spiritHe bought an apple, two oranges, a banana, and a bag full of lemons.
In the last case, if you have "a banana and a bag full of lemons" it could be interpreted that the banana and bag are full of lemons (For clarity, adding the comma is a good idea).

I believe a comma is not needed in BrE.

Being from New Zealand, and essentially writing in "British English", I can tell you that Universities here suggest using the 'Oxford comma' (which my name alone suggests its usage in British English). See:

It could be interpreted that the banana and bag are full of lemons.

I don't think it is likely that anyone will interprete the OP's sentence to mean the above. That's why I think a comma is not needed in BrE. I believe, in AmE, a comma is needed.

Hi,
I grew up in Britain and was educated at Oxford, and the first time I ever heard of this 'Oxford comma' was a few years ago when I started on this Forum.
I must have missed something.

Yoong LiatI don't think it is likely that anyone will interprete the OP's sentence to mean the above. That's why I think a comma is not needed in BrE. I believe, in AmE, a comma is needed.

That may be the case, however adding punctuation in appropriate places aids clarity and is a good habit to develop. That is my personal opinion. It is a matter of style and