It is possible that customers using later versions of Safari on IOS devices may see a message regarding a ‘token mismatch error’.
Two options to resolve this issue are:
1) Update settings in safari
Navigate to Settings > Safari
In the ‘Privacy and Security’ section please disable "Prevent Cross-Site Tracking" and "Block All Cookies"
The above steps should be completed before you proceed to checkout.
If this doesn’t resolve the error it may be necessary to remove all items in your basket, close your browser window, repeat the above steps and add items to your basket
2) Use a different browser or device
If you do not wish to change settings in Safari you can use an alternative browser on your IOS device like Chrome, or use a different device to place your order