Hi Paul,
If you change the most recently created invoice number to the number you require, what happens is that FreeAgent remembers the last number in sequence then generates the next invoice with a reference number 1 up from that - so for example, if your last invoice was 501 and you are using global level invoice sequencing, FreeAgent will create the next invoice as number 502.
Here is a link on how the invoice numbering schemes work in FreeAgent;
http://www.freeagent.com/support/kb/i...
Here's some information on the security of FreeAgent to help persuade your wife:
http://www.freeagent.com/support/kb/g...
You may be interested in our referral scheme which is a way you can benefit from discounts by referring new paying customers to us. Please read the following link for more information on this;
http://www.freeagent.com/support/kb/m...
If you have a look at our Community Forum at
http://community.freeagent.com/freeagent you may be able to find a referral code there, or simply start a new thread on the forum and ask for a referral code and I am sure you will have some willing providers. Alternatively, you could post a tweet to say that you're looking for "a referral code for @freeagent" and you will receive plenty of responses!
I hope this helps :-)
Kind regards
Janice