Paypal subscription free trial isn't working

Question

I'm using the following form, but the customer is charged immediately and doesn't get the 5 day trial. I have no idea why. I tried this with the sandbox and on the "regular" paypal site. What do I miss here?

<form action="https://www.sandbox.paypal.com/cgi-bin/webscr" method="post">
<input type="hidden" name="business" value="xxx@xxx.com" id="id_business"/>
<input type="hidden" name="item_name" value="xxx" id="id_item_name"/>
<input type="hidden" name="item_number" value="1" id="id_item_number"/>
<input type="hidden" name="a1" value="0" id="id_a1" />
<input type="hidden" name="p1" value="5" id="id_p1" />
<input type="hidden" name="t1" value="D" id="id_t1" />
<input type="hidden" name="a3" value="14.95" id="id_a3" />
<input type="hidden" name="p3" value="1" id="id_p3" />
<input type="hidden" name="t3" value="M" id="id_t3" />
<input type="hidden" name="src" value="1" id="id_src" />
<input type="hidden" name="sra" value="1" id="id_sra" />
<input type="hidden" name="no_note"value="1" id="id_no_note"/>
<input type="hidden" name="modify" value="1" id="id_modify" />
<input type="hidden" name="lc" value="US" id="id_lc" />
<input type="hidden" name="notify_url" value="http://xxx/payment/paypal-ipn/" id="id_notify_url" />
<input type="hidden" name="cancel_return" value="http://xxx/payment/canceled/" id="id_cancel_return" />
<input type="hidden" name="return" value="http://xxx/payment/thank_you/" id="id_return_url" />
<input type="hidden" name="custom" value="user=joe;db=1" id="id_custom" />
<input type="hidden" name="cmd" value="_xclick-subscriptions" id="id_cmd" />
<input type="hidden" name="charset" value="utf-8" id="id_charset" />
<input type="hidden" name="currency_code" value="EUR" id="id_currency_code" />
<input type="hidden" name="no_shipping" value="1" id="id_no_shipping" />
<input type="image" src="https://www.sandbox.paypal.com/en_US/i/btn/btn_subscribeCC_LG.gif" border="0" name="submit" alt="Buy it Now" /></form>

Answer 1

Looks like you need to set modify to 0.

At least now it is working for me again.