Contract costs comprise mainly incremental customer acquisition and retention costs. Movements in the contract costs balance for the 12 months ended 31 December 2020 and 2019 were as follows:
At 31 December
2020
At 31 December
2019
Non-current contract costs
106
99
Current contract costs
368
329
Total contract costs
474
428
12 months ended
31 December 2020
12 months ended
31 December 2019
Beginning of period
428
353
Contract costs recognised as assets
551
568
Contract costs expensed
(503)
(488)
Impairment, net
(2)
(5)
End of period
474
428