Spreading the deduction and tax capacity

A deduction is not used in one go but spread over equal annual instalments, starting from the year in which the expenditure is incurred. Each instalment can be used only in the year to which it relates.

For the main building deductions the relief is spread over ten annual instalments. The benefit is therefore a flow and not a single amount.

The financial effect is substantial and should be communicated precisely. A deduction used over ten years is not equivalent to an immediate discount of the same amount, for two reasons: the financial value of the deferral, and the risk that one or more instalments cannot be used.

Presenting the deduction as a discount on the cost of the works is therefore a simplification overstating the advantage the client perceives. The correct presentation shows the annual instalment.

A deduction reduces the tax due and therefore presupposes that tax exists. Where no tax is due the instalment goes unused.

A taxpayer without gross tax sufficient to absorb the annual instalment in a given year loses the excess. It is neither refundable nor carried forward.

The loss is final and concerns the individual instalment. A taxpayer without capacity in one year and with capacity the next uses the second year's instalment and has lost the first.

This is the aspect a superficial check overlooks. It concerns the horizon over which capacity must be assessed.

Because the relief runs over ten tax years, capacity must be checked not for one year but for all those over which the deduction is spread. The assessment belongs to the tax adviser.

A client with capacity at the time of the works may not have it in five years, for foreseeable reasons such as retirement or a reduction in activity, or for unforeseeable ones. The risk should be flagged rather than concealed.

The consequence for the feasibility assessment is that the benefit should be treated as a flow subject to risk rather than as a certain amount. The uncertainty should be stated in the estimate.

For clients whose annual tax is of the same order of magnitude as the instalment, the check is worth carrying out with their tax adviser before committing to the works. The check costs little and changes the decision.

Mechanism	What it operates on	Effect where it bites
Tax capacity	Tax due for the year	The year's instalment is lost and cannot be recovered
Income cap	Annual deductible expenditure	The amount on which the deduction is calculated falls
Ten year spread	Distribution of the deduction	The benefit is a flow and not a single amount

Two distinct mechanisms can reduce use, and should be kept separate because they operate differently. They are tax capacity and the income cap.

Tax capacity is a question of available tax: if the tax is absent, the instalment is lost. A lost instalment cannot be recovered in later years.

The cap applying to taxpayers with total income above the threshold is a limit on deductible expenditure, operating independently of capacity and reducing the amount on which the deduction is calculated. The cap must be tested against all deductible charges.

A taxpayer may therefore have capacity and still be limited by the cap, or fall outside the cap and lose the instalment for want of capacity. The two mechanisms must be checked separately.

One rule greatly softens the cap's effect on building deductions: for charges deductible over several years, only the instalment for the year counts. A ten year project therefore affects the cap by one tenth of the expenditure.

Until the general block introduced in past years, a taxpayer without capacity had two ways of monetising the benefit: transferring the credit and taking a discount on the invoice. Neither route is available today as a matter of course.

Today the availability of those options is residual, confined to the situations the rules preserve. What remains should be checked case by case.

The principle is therefore reversed: the rule is direct use in the tax return, and the alternatives are the exception. Direct use is therefore the assumption to make in estimates.

The practical consequence is that checking tax capacity has returned to the centre of the feasibility assessment. A client without sufficient tax capacity no longer has, save in exceptional cases, a way of recovering the benefit, and for them the works cost the gross amount.

Three points close the picture and delimit the professional's role. They concern the check, the warning and the form of the estimate.

Calculating tax capacity does not belong to the technical professional. It requires knowledge of the client's overall tax position and is a matter for their adviser.

Flagging that the issue exists does belong to the professional, because it is they who present the estimate and introduce the amount of the deduction into the discussion. The warning should be given in writing in the estimate.

The correct form of the flag is a stated assumption: the estimate gives the resulting annual instalment and states that actual use depends on the client's tax capacity, referring the question to their adviser. The referral to the adviser delimits the scope of responsibility.

One final observation. On substantial projects for private clients, the outcome of that check can change the scale of the works. Bringing it forward is therefore also a way of avoiding a redesign at an advanced stage.

Presenting the deduction as an immediate discount is the first, and is the most widespread simplification. The benefit is a ten year flow and not a reduction in price.

Checking capacity for a single tax year is the second, and ignores the ten year horizon. The assessment should cover the whole spreading period.

Confusing tax capacity with the income cap is the third: they are distinct mechanisms that can operate together. The two mechanisms can reduce the benefit together.

Assuming credit transfer remains available as an exit route is the fourth, and no longer matches the regime in force. What remains is very narrow.