Can the system chase a customer for their balance payment on its own before the due date?

Yes, balance reminders are one of the easiest parts of the booking process to automate, as long as the booking carries a due date the system can read. Once a deposit is taken and a balance date is stored against the booking, reminders can be scheduled from that date and sent by email or message without anyone in your office remembering to look.

Most agencies set two or three reminders, one a couple of weeks ahead, one a few days ahead and one on the day itself, and stop them the moment the balance is settled. The stopping part matters more than the sending part, because nothing annoys a traveller faster than being chased for money they have already paid, so the reminder should always check the payment status before it goes out.

Where this gets less automatic is collecting the money itself. If your payment gateway supports a payment link, the reminder can carry that link and the customer can settle it without speaking to anyone. If it does not, or if the booking was taken offline and never had a payment record, the reminder can only prompt the customer to call you. Supplier deadlines are a separate matter again, because the date the supplier will release the booking is not always the same as the date you asked the customer to pay.

Check first that every booking you take, including the offline ones, has a balance due date recorded against it, because reminders can only be as reliable as that date.