Negative income or losses from services can be offset against profits from similar income in the same year. At the same time, it must be clear that you could also achieve a surplus with the other services. Otherwise, the losses from the services will not be recognised, but you do not have to pay tax on the income either.
If the income from services is negative, it can be carried back to the previous year and offset against similar profits made there. You can also carry the losses forward to the following year and offset them against the surpluses then presumably achieved. By carrying back or forward the losses, you reduce your taxable income in the relevant year.
