This part of GOV.UK is being rebuilt – find out what beta means

HMRC internal manual

Oils Technical Manual

Receipts into warehouse: receipts from customers’ tank cleaning services: oil returned other than to duty-suspended storage or Remote Marking Premises

In exceptional circumstances, where contaminated or accidentally mixed product cannot be returned to duty-suspended storage, you may permit treatment to take place elsewhere under control, but no duty credit can be allowed in these circumstances. Even if it is taken to a remote marking premises, there is no tax credit claimable, as an RMP is not a tax warehouse.

At some distribution warehouses which are neither duty-suspended installations nor RMPs, small quantities of contaminated or mixed oil (e.g. flushings) are sometimes returned to bulk stocks of rebated oil without the addition of markers. No objection need be raised to this practice provided the contamination or mixture does not exceed 5% of the actual tank contents at the time the return to stock is made.

Where there are a number of such returns, care must be taken to ensure that the quantity does not exceed 5% in aggregate.