Your Amazon Prime trial is completely free, however, you will need to cancel your membership before it activates beyond the 30 day expiry of the trial to avoid a payment being taken.

Prime Now is the ultra-fast, super convenient delivery service available on thousands of household essentials and groceries. Whether you’re running low on milk or want to stock up with a weekly shop, all items are handpicked at your local grocery store and delivered to your doorstep the very same day. It’s free for all Prime members!

There isn't Amazon Prime discount codes to reduce the cost of Prime subscriptions. However, with a bit of planning there are ways to get a better deal on your Prime membership:

• If you're a student, Amazon offers a "Prime Student" version at a reduced rate, often including an extended free trial.
• Watch out for free trial periods of Prime itself. Joining for a 30-day free trial gives you full access to benefits and allows you to evaluate whether the subscription is worth it.
• During major sales events (like Prime Day, seasonal promotions or bundle offers), you can benefit from cost savings on purchases or decisions around when to subscribe.
• Make use of other membership perks you already pay for (or cross-check if an employer/organisation offers discounts) and consider cancelling if you're not using enough of the Prime benefits. Then you'll essentially get "value" even if there's no direct code.