Starting from the “Accounts Menu”…
What is Lock Down?
The lock down does absolutely nothing except protect your data from being accidentally changed. For example, having made sure your accounts are correct up to the end of December 2003 you could then impose a lock down on any further changes prior to that date, for example to stop people accidentally posting invoices dated Jan 1st 2003 instead of Jan 1st 2004. You should use this facility on a regular basis. To remove or change the current “Lock down” dates you simply clear or edit them. Note that the dates entered cannot however precede the most recent period end, which also acts as a lock down. If you wish, you can set different lock down dates for each of the various aspects of your system.
If you are VAT registered you are most strongly recommended to set a lock down immediately after completing each VAT return, which will prevent any retrospective changes to the VAT in the accounting quarter you have just submitted.