16/10/2026
A customer pays you £1,200. How much of it is yours?
If you're VAT registered and charging the standard rate, £1,000. The other £200 belongs to HMRC and is only resting in your account. There's tax on the profit still to come out of the £1,000 too.
The trouble is that the bank shows one number. £1,200 lands, the balance looks healthy and decisions get made with money that was never available. Three months later the VAT return is due and the balance has to find it.
What works is pretty boring: a second account, and the habit of moving the tax share across on the day each payment arrives. Out of sight, not spent.
I can work out the right figure for your business from your last few quarters.