This is due to your some input is missing &or overlook &or not according to steps.
Billing & Delivery. The steps as follow:
1. To start, select Delivery Method: "Home Delivery" or "Self collect".
2. Delivery Address: If same as billing, do click on the right side "Billing Address".
3. Continue to next: Input your Name, and Contact Number" mandatory. They will contact you for confirmation on the your order.
4. Next: click on "Select date" drop down box and select.
5. On "Select Time" drop down box and select. If not available, go back "Select date" and choose a later date.
6. Lastly, read the paragraph and selected accordingly, if nec to change.
7. Finally, below select "Next".
Do note you have to follow according to the steps.
At Checkout, Do review your input detail.
Finally is the Payment.
I am not Starhub staff &or related to.
Do clear your browser cache and try again.
Should you still face an error, you call 1630 to complete your sign up.