Software: MoneyWorks accounting software
You never need to purge your valuable transactions from MoneyWorks, unless you want to (or your file is enormous and approaching the four gigabyte limit). This means that you never need to discard your valuable transaction data, something that is particularly important when looking at historical information for your customers.
But you do need to manage your periods (under Command>Open/Close Period). In particular:
If you don’t close your periods, MoneyWorks will (after about seven years), refuse to open any more. Should that happen, simply go in and close the old periods from seven years ago.