5. Finance income and cost
 
2020
R'm
  2019
R'm
 
Finance income (93)   (60)  
   Interest revenue calculated using the effective interest rate method (4)   (1)  
   Foreign exchange gains (80)   (54)  
   Other (9)   (5)  
Finance cost 918   1 058  
   Interest-bearing borrowings and bank overdrafts 501   674  
   Interest rate swap contracts 40   16  
   Interest on lease liabilities 158   65  
   Borrowing cost capitalised¹ (9)   (8)  
   Preference shares 29   142  
   Foreign exchange losses 56   66  
   Unwinding of contingent consideration 66   44  
   Other 77   59  
Net finance cost 825   998  
1 The Group has used an average rate of 7.8% (2019: 8.7%) in determining the borrowing costs capitalised.