At 31 December: 2019 2018 HK$'000 HK$'000 Trade receivables 24,025 20,172 Less provision for impairment of receivables (212) (262) Trade receivables - net 23,813 19,910 Trade and other receivables 43, 114 36,433 Prepayments and deposits 49,620 54,865 92,734 91,298 The company's sales to customers are mainly on a cash basis. However the company allows credit of between 30 to 45 days to corporate customers for the provision of the corporate catering services. The ageing analysis of trade receivables is as follows: At 31 December: 2019 2018 HK$'000 HK$'000 0 - 30 days 31-60 days 14,315 12,709 4,936 61 -90 days 4,438 Over 90 days 1,420 1,008 3,354 2,017 24,025 20,172 Sales to corporate customers were HK$203,900,000 in the year to 31 December 2019. (2018: HK$188.790.000)