“Will your donation be small change for a big business?"

• Check the usual suspicious things: what proportion of their income does the charity spend on overheads (though charities are getting good at hiding this: even consultants can be classed as frontline staff)?
• Do they use volunteers (not including fundraising volunteers)? If so they probably need your money. And homeless people like volunteers - they have less luggage than paid staff.
• How much money do they get in Government contracts? Will your donation really make any difference, or will it be small change for a big business?

“Homelessness is notoriously difficult to count"

• Be very suspicious of charities whose primary purpose de facto is campaigning and lobbying. You will be paying to support an ideology, not a service. Homelessness charities continue to campaign for more and more public housing in areas where there are already surpluses of public housing. The well-paid public sector worker with the final salary pension will always call the needs of the very worst-off in aid of their own survival. It’s an unholy alliance which relies on an endless supply of misery. Heaven forbid that homelessness should be solved; a lot of people would be unemployed.
• A similar point: be suspicious of a charity that vaunts above all else its values. Your donation should not shore up their ethical credentials. You should be interested in the values that they are inculcating into the people they work with. Their own values are important, but they are not by any stretch of the imagination a good cause.
• Homelessness is notoriously difficult to count. Treat all numbers with a handful of salt. Believe the evidence of your own eyes. Homelessness charities may tell you that there are hundreds of thousands of homeless people, but where are they? If you can’t see them and no one else can, you should smell a fundraising rat.