How Scottish Aggregates Tax works

This is an introduction to Scottish Aggregates Tax. This introduces general terms and concepts and provides an overview of the tax. Specific technical guidance is included in each of the chapters below.

1. What aggregate is
2. How the tax is calculated
3. Commercial exploitation
4. Exemptions
5. Who is liable to pay the tax
6. Unregistered supplies

What aggregate is

Aggregate includes any rock, gravel, or sand, along with substances naturally occurring together with them or incorporated in them. If a material is mixed with rock, gravel, or sand at the time of extraction, it is still considered aggregate for Scottish Aggregates Tax. 

Some materials resulting from processing aggregate remain taxable, while others do not. Spoil, waste, and by-products from some ‘excepted processes’ remain taxable, but finished products are not. 

‘Excepted processes’ include: 

1. Cutting of rock to produce stone with flat surface(s)
2. extracting or separating ‘relevant substances’ from aggregate
3. producing lime or cement from limestone (including chalk or dolomite) or limestone and anything else
4. using shale for non-construction purposes 

Further detail on ‘Excepted Processes’ and ‘Relevant Substances’ is provided in Exemptions - Excepted Processes. 

How the tax is calculated

The amount of tax charged on aggregate is calculated by multiplying the current rate of Scottish Aggregates Tax (SAT) by the weight in tonnes of the taxable aggregate. 

SAT rate x Weight of taxable aggregate in tonnes = Tax charged 

To calculate the weight of aggregate a weighbridge should be used that complies with the Weights and Measures Act 1985, and that is located on the site where the aggregate is first commercially exploited. 

If the use of a weighbridge is not possible, an alternative weighing method must be agreed with Revenue Scotland. This is a formal written agreement that sets out the method which the weight will be calculated and the time it must be calculated by. This agreement can be withdrawn, or varied by Revenue Scotland should it be deemed necessary, for example, because it does not give an accurate indication of the weight or the method is not being fully observed. 

Revenue Scotland can require that an alternative weighing method is used should a suitable alternative not be agreed. Revenue Scotland can also specify a weighing method in guidance if it is considered necessary. 

More detail on weighing methods can be found in the Tax Calculation guidance. 

Commercial exploitation

Scottish Aggregates Tax is charged on aggregate when it is subject to ‘Commercial Exploitation’ in Scotland, unless it is Exempt Aggregate. Exempt Aggregate is defined in Exemptions – Exempt Aggregate. 

Broadly, aggregate is considered ‘commercially exploited’ if, as part of a business activity: 

1. it is removed from a site
2. an agreement has been made to supply it to a person
3. it is used for construction purposes, or
4. it is mixed with a material or substance that is not water, unless in ‘Permitted Circumstances’ 

Commercial Exploitation happens in Scotland if the aggregate is exploited in Scotland, including, where the aggregate has been moved from outside Scotland for exploitation in Scotland. This may include imports from overseas and movements from the rest of the UK before exploitation in Scotland. Special rules apply to material arriving in Scotland from elsewhere in the UK before exploitation in Scotland (see Commercial Exploitation). 

Exemptions

There are certain conditions which make aggregate exempt from Scottish Aggregates Tax. A quantity of aggregate is exempt if:

1. it has already been subject to Scottish Aggregates Tax
2. it has already been used in construction (recycled aggregate)
3. it was stored on a site other than the originating site prior to 1 April 2026, except where it is stored on another site of the registered operator
4. it is extracted as a necessary part of construction work
5. has been dredged from a watercourse to create, maintain or improve that watercourse
6. it is wholly the spoil from separating a coal, lignite, slate or any ‘relevant substance’
7. is wholly, or mainly, a specified substance  

Further detail of these exemptions is provided in Exemptions. 

Who is liable to pay the tax

The person(s) liable to pay Scottish Aggregates Tax are those persons(s) who are responsible for subjecting it to ‘Commercial Exploitation’. This will depend on the type of commercial exploitation that has taken place. If aggregate has been commercially exploited in Scotland, and has been subject to a Scottish Aggregate Tax charge, any subsequent exploitation will be exempt from the tax. The table below details the person(s) responsible for paying the tax in each type of Commercial Exploitation.

A person responsible for commercially exploiting aggregate only does so if it is in the furtherance of a business carried on by that person. The phrase ‘furtherance of business’ includes public sector and governmental organisations, charities and not for profit organisations. 

A ‘Connected Site’ is one different to the originating site but still under the registered operator’s control, or under the same registration for Scottish Aggregates Tax. 

Unregistered supplies

If you purchase aggregate from a person who is not registered for Scottish Aggregates Tax but should be then you may become jointly and severally liable for the Scottish Aggregates Tax that should have been paid at point of supply.

Please see the [Unregistered Supply] section for more details