How to create a modify subscription button?

[alante1]

I've a number of users who have subscribed to my organization at a fixed annual rate which has now been changed. I can't modify their payment and nor can they.  So I thought I'd make a 'Modify payment button' as a one time use, so they can authorize the new subscription level. I found some sample code to do this on Paypal help and modified it to include my site details. I then setup a subscription from myself to pay a subscription of £1 annually. Then using the modify button I'd created, I tried to use it to modify my subscription to £2. It took me to my Paypal page and then said "Things don't appear to be working at the moment. Please try again later."

This is the code I am using:

<form action="https://www.paypal.com/cgi-bin/webscr" method="post">

    <!-- Identify your business so that you can collect the payments. -->

    <input type="hidden" name="business" value="mysite">

    <!-- Specify a Subscribe button. -->

    <input type="hidden" name="cmd" value="_xclick-subscriptions">

    <!-- Identify the subscription. -->

    <input type="hidden" name="item_name" value="FF Subscriptions">

    <input type="hidden" name="item_number" value="Modify">

    <!-- Set the revised subscription price and terms. -->

    <input type="hidden" name="currency_code" value="GBP">

    <input type="hidden" name="a3" value="2">

    <input type="hidden" name="p3" value="12">

    <input type="hidden" name="t3" value="M">

    <!-- Set recurring payments until canceled. -->

    <input type="hidden" name="src" value="1">

    <!-- Let current subscribers modify only. -->

    <input type="hidden" name="modify" value="2">

    <!-- Display the payment button. -->

    <input type="image" name="submit"

    src="https://www.paypalobjects.com/en_US/i/btn/btn_subscribe_LG.gif"

    alt="Subscribe">

    <img alt="" width="1" height="1"

    src="https://www.paypalobjects.com/en_US/i/scr/pixel.gif" >

</form>

 Please tell me what I'm doing wrong.

[not_here]

Hi @alante1,

Unfortunately we've deprecated the modify feature in our classic subscription product (as seen in the post Important Notice regarding upcoming Subscription Changes). 

You will find the documentation for our Subscriptions API is here. There you will find an integration guide that will help guide you through the process of using this new product. 

Hope this helps!
Thanks,
Christina 

[alante1]

Hello,

I don't understand your reply. By 'deprecated' do you mean the ability to modify a subscription has been removed? And that it is possible to do that if I use soemthing called Subscription API instead? I read the instructions for subscrition API but couldn't see anyhting to tell where where to get hold of it. IS this soemthign I ahve to pay for? IF so, can you point me to the page where it tells me how to obtain it?

Thanks.

[pabloapico]

It looks like paypal subscription service is incomplete; at least, for subscriptions using a variable quantity model.
We have tested the api and yes you can update a subscription quantity but it would take effect only in the next billing cycle. In a yearly billing cycle that could be many months away...
So, one would have to charge the current period change in some other way... Not good.
What we have been doing is to tell our customer to cancel the subscription entirely and start a new one.... so we do a refund.
But that is also bad. However, so far it is the only solution we have found out.

This issue is either lack of documentation on PayPal's API or lack of essential features of a subscription service.

Am i missing something?