Ayodele:

If you want to send invoices to customers every month, week, bi-weekly, annually for any amount you can use recurring entries. You will need to create them first, then when finished store your recurring invoice with whatever recurring period you want, save it and send/print and post if you are completed. Once you have created all of your invoices you can use the daily business manager to send them out the next time if they are identical to what you first stored them as. Once your entries are stored you can also go into your usual create a sales invoice screen and recall the invoice to make any changes.