If you make a payment out or spend tally (milligrams of gold) at a lower GBP price than the GBP buy price, you realise a capital loss on that transaction. Any losses are included in the calculation of the final capital gain/loss on your TallyMoney transactions for the tax year, at the end of the tax year. If a capital loss is calculated at the end of a tax year, the loss can be used to offset other capital gains that occurred in that same tax year or carried forward to future tax years.