Not that great of a saving but a easy 5 if you are planning on spending a 100 on amazon in the near future (know i will spend it before Christmas anyway).

edited-

some people seem to be able to use this offer and an older offer of "3 pound when you top by 60" all when they do a single top up of a 100. so are getting 8 pounds free with 100 top up.

so might be work it to try this as well

https://www.amazon.co.uk/b?ie=UTF8&node=10638201031

update - 3 pound top up no longer working.

What is Top Up?

When you use Top Up, you are effectively purchasing an Amazon.co.uk Gift Card that is automatically added to your Amazon.co.uk Gift Card balance. You can directly and instantly top up an amount of your choice using a credit or debit card. You can also set up Auto Top Up, with the option of scheduling a Top Up on a regular frequency, or adding funds automatically when your balance drops below a selected amount.

Try Top Up today and get an extra £5 when you Top Up £100 or more.

To enjoy this special offer, you must:

(1) be the recipient of the corresponding offer on Amazon.co.uk,

(2) click the button 'Click to qualify for the Top Up reward’ below to see if you are eligible for the offer,

(3) Top Up £100 or more in a single order on Amazon.co.uk.

We'll automatically apply the £5 reward to your Gift Card balance and confirm by e-mail after your qualifying Top Up order has been processed.

Terms and Conditions of the Promotion

Get an extra £5 added to your Gift Card Balance when you Top Up £100 or more in a single order on Amazon.co.uk ("Offer"). In order to qualify for the Offer, you must: (1) be the recipient of the corresponding Offer on Amazon.co.uk; (2) click the button 'Click to qualify for the Top Up reward’; and (3) Top Up at least £100 in a single order on Amazon.co.uk.

For qualifying orders, an additional £5 will be automatically applied to the Gift Card Balance of the Amazon.co.uk account used for Top Up, after the qualifying Top Up order has been processed. In the case of Auto Top Up, the reward will be applied after the order is processed and delivered to your Gift Card Balance. An email notification will be sent to you to confirm the application of your £5 Amazon.co.uk Gift Card reward.

The amount processed in your Top Up order and the £5 reward can both be checked on the Gift Card Balance page.

The Offer is limited to one £5 Amazon.co.uk Gift Card reward per customer/primary e-mail address.

This Offer may not be combined with any other promotional offer.

Amazon may change or withdraw this promotion at any time at its sole discretion.

In the event of a cancellation of the Top Up order, the reward amount will also be cancelled.

When you Top Up, you are purchasing a Gift Card for the selected amount that will be automatically added to your Gift Card Balance, which may be redeemed on the Amazon.co.uk website towards the purchase of eligible products listed and sold on Amazon.co.uk.

Gift Cards, including any unused Gift Card balances, expire 10 years from the date of issuance. GCs cannot be resold, transferred for value, redeemed for cash or applied to any other account. Amazon.co.uk is not responsible if a GC is used without permission. For complete terms and conditions, see http://www.amazon.co.uk/gc-legal. GCs are issued by Amazon EU S.à.r.l. All Amazon ®, ™ & © are IP of Amazon.com, Inc. or its affiliates.