Higher Rate pension relief

Im trying to determine what additional tax relief on pension contributions I can claim as part of self assessment as a PAYE Scenario: Compiling PAYE tax return Higher rate tax payer (40%) on £10000 p.a. of salary Pays £10000 p.a into workplace pension using relief at source Pension provider add basic rate(20%) relief = £ 2500 Question: I am unclear how the addition 20% that can be claimed is calculated It could be: a). 20% relief on £10000 = £2500 or b). The difference between 40% relief on £10k and the 20% relief on £10k already claimed by pension provider That is (5/3)*10000 -(5/4)*10000= 16666.67-12500= £4166.67

Hi revolver1 Ambrose,
If you are a higher rate taxpayer and the contributions are deducted from your salary before tax then you would already have received the relief and no further tax relief due.
If from your net income then the pension provider will  receive 20% tax relief and if you are higher rate you would be entiled to additional 20% relief. 
Thank you.