What’s the situation, are you working or on maternity leave and only on ssp?
We put all of our income together, get the bills out + a bit in savings and then whatever is left gets halved to each other. Say there's £200 left, we get £100 each to spend for the month.
We have an account we both pay into for bills and anything for our boy.
We set aside money from our combined income for each of us to use for whatever we want each month and if there's something I need or want and don't have the money for I just ask him and he either gets me the item or sends me the money to get it