We are migrating to Zoho billing and have some existing customers who are billed in arrears. This is a legacy thing, so not how we plan to bill going forward. There isn't any major issues migrating these existing subscribers; they simply get billed on the next billing cycle.
The only thing to remember is they owes us, not the other way round if they cancel. Zoho will give them a credit if they cancel, but we then need to charge them for an extra month. It would be nice if this was a single pro-rated charge (not credit). Things start go get very complicated when people upgrade plans. They will get billed right away, but we then need to credit them to maintain their arrears billing correctly.
Has anyone else tried to manage both types of billing? Ideally it would be a setting that could be set on the CRM account and then synced over to subscriptions (Bill in Arrears? true/false). We can deal with this issue but it complicates things.