Will I be charged delivery in Asda

[empatheticpretzel]

You have to spend £40 if you spend less there's a £3 charge. My basket comes to £50 but I have used a rewards voucher from all my saved up points that brings it to £30. Will I be charged £3?

I don’t think so - the value of your basket is still over £40, you’re just using a voucher for part payment.