Direct debit date

So my Direct debit was the 5th of each month and the Bulb bill was generated on the 3rd that meant for a couple of days my balance dropped enough to get a balance not healthy note. 2 days later when Direct debit was paid I get a balance healthy note. To stop this from happening I moved my Direct debit date to the 3rd but then Bulb move thier bill generation date to the 1st making my balance again low for 2 days. Please explain.

The bill date is determined by your payment date, as you have discovered.

If you want to ensure you don’t get the “balance not health” note I’d suggest either temporarily increasing your payment to build up a larger buffer, or make a one-off top up payment into your account. Both can be done via the web dashboard, unsure about via the app.