We ask for meter readings every three months?

What if I’m on holiday and can’t send meter readings? – Bulb says After you submit your first readings, we ask for meter readings every three months. This ensures your estimate is accurate. Ideally, you would submit a meter reading every month, two days before your payment date.

This could be seen as somewhat contradictory and confusing to some.

Why contradictory because Bulb do in fact send out monthly (not every three months) statement reminders suggesting supplying meter reading for accurate bills.

Could the wording be amended to say something like “After you submit your first readings we ask for meter readings each month two days before your payment date, This ensures your statement is accurate. Otherwise you must submit meter readings at least every 90 days.”

Seconded.
I note also that the acknowledgement email I receive when submitting a reading contains the following:

We've received your electricity meter reading. Thanks so much.

Another reading in about 3 months would be ideal to keep things shipshape.

Ideal? I think not.