For everyone elected to the 2016 Democratic State Convention in Lowell, note the following language from the Call to Convention:
The registration fee of $75.00 per delegate must be posted or mailed by the Delegate/Alternate by April 8th, 2016. A late fee of $25.00 will be due with each Delegate/Alternate registration received or postmarked after the April 8th, 2016 deadline.
You can pay it online, but the state Democratic Party doesn’t make it easy. Competing for the worst website ever award, you need to mouse yourself to an obscure corner of the thing to find the registration/payment links.