I use following html to create paypal subscription:
<form action="http://paypal/url/..." ...>
<input type="hidden" name="cmd" value="_xclick-subscriptions">
<input type="hidden" name="business" value="selleremail@somedomain.com">
<input type="hidden" name="item_name" value="My Subscription">
<input type="hidden" name="currency_code" value="GBP">
<input type="hidden" name="p3" value="1">
<input type="hidden" name="t3" value="M">
<input type="hidden" name="tax" value="0.00">
<input type="hidden" name="no_shipping" value="1">
<input type="hidden" name="shipping" value="0.00">
<input type="hidden" name="no_note" value="1">
<input type="hidden" name="src" value="1">
<input type="hidden" name="cancel_return" value="http://mysite/paypal/cancel.page">
<input type="hidden" name="return" value="http://mysite/paypal/success.page">
<input type="hidden" name="notify_url" value="http://mysite/paypal/ipn.page">
</form>
Everything works well, new subscriptions are created, IPN notifications are got by my scenario. One thing is bother me. If some payment is failed, appropriate subscription becomes suspended. It happens due to default settings of a subscription. There is set 1 failed payments allowed before suspending subscription profile.
I can turn it off manually as described in documentation, but how to setup it on subscription creation stage? And is it worth to turn off it or better to set some number of fails?