I have discovered something new about money. If you divide it up and give someone ownership then it doesn't disappear so quickly!
Since Christmas we are trying something different. I am control of my salary, child benefit, the old chaps 2nd salary (which is hugely variable) and house-keeping contribution from Ahdel. From this I must pay all of th bills and any mortgage over-payments that I can. The petrol and other travel expenses, food and groceries.Anything left over goes to the holiday fund. We use a joint account into which everything goes. We don't use jam jars or envelopes, just analyse spend at the end of the month to make sure we haven't strayed and to help re-enforce sensible habits.
The old chap gets control of money from his 1st job. This finances our property investments but also helps out with major car repairs and misc, ad hoc expenses. I don't really have much to do with this area unless he asks for my thoughts so this suits us both. If all goes well we should get income from here eventually to repay the mortgage early.
Other income, quidco, ebay, mileage and expenses goes to the holiday fund.