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HMRC internal manual

Customs Special Procedures Manual

Inward Processing - conditions and requirements: rate of yield (ROY)

It is particularly important that the rate of yield is accurate as this determines the amount of customs charges that will be suspended. If the rate of yield is too low, the authorisation holder could fraudulently discharge goods to free circulation.

When goods are entered to IP, the amount of customs charges initially suspended will depend on the quantity of goods entered to IP that are contained in any Main Processed Products (MPPs - see SPE13025) which are (re-)exported or put to a disposal that discharges IP.

Unless the processing operation is something such as repair and return where the rate of yield would be expected to be 1:1, applications may refer to use of production records but must identify the specific type of records that will be used. In these cases the actual rate of yield achieved must then be established through post authorisation checking of the trader’s production records. This should be carried out before the goods are put to a disposal that discharges IP or at the latest when the Bill of Discharge is submitted.

Where more than one product is obtained a rate of yield for each product including by-products (Secondary Processed Products (SPPs)) must be established (see SPE13030). Some examples of how to establish a non-standard rate of yield are set out below.

Rate of yield example calculations

Goods entered to IP are incorporated into a finished product without loss

*Example *5 buttons used per processed product Rate of yield = 5:1


Goods entered to IP are used to manufacture a product. The rate of yield is established by dividing the quantity of processed product produced by the quantity of goods entered to IP used in producing that quantity

*Example *500 kg of goods are entered to IP from which 2500 litres of processed product are produced, the rate of yield = 2500/500 = 5 litres per kg


When more than one product is produced and the goods entered to IP lose their identity during process. The rate of yield must be established for each product produced.

*Example *500 kg of IPR goods (A) produce: 1,000 litres of product B and 150 kg of product C

The rate of yield should be expressed as: 500 kg (A) produce 1000 litres of (B) and 150 kg of (C)

Council Regulation (EU) 952/2013, Article 255; Notice 3001/2015, Annex D, Sections 1.2 and 2.8

Production losses

To allow your rate of yield to be verified and to ensure you obtain the full amount of relief you are entitled to we need to be aware of any losses that arise during processing, eg, through evaporation, desiccation, leaching or venting as gas. These losses should be subtracted from the quantity of import goods prior to establishing the rate of yield. For the purposes of duty relief any by-products of the processing operation are not to be treated as production losses. Duty liability in respect of any production loss must be included in the duty liability of processed products.

Notice 3001/2015, Annex D, Section 2.8