Changing address -- not receiving invoices

Hi,
I have moved to a new address within Germany and I am wondering how the debt collection process would work if an invoice is sent to the old address and it couldn't be delivered? Does this trigger a debt collection process which I don't find out about until much later?

You are responsible for making sure letters to the old address reach you for a certain time after moving (I think it's 6 months). The German Post offers "Nachsendeauftrag" for this purpose, but you can also make arrangements with your landlord, the new tenants, or whoever.
If you leave a bill open due to this, the debtor can get your new address from the registration office and contact you there. Of course this will cause delays and additional costs.

Thanks. I think I will contact all potential sources of bills and inform them of my new address. The nachsendeservice would be good if one can't keep track of all potential sources.

As long as the debtor gets my new address, and debt collection costs don't accumulate for years while they search for my new address, then its fine with me.