Accounts receivable
 12 Months Ended
Oct. 31, 2021
Trade and other current receivables [abstract]  
Accounts receivable Accounts receivable
Aging SummaryOctober 31, 2021October 31, 2020
$$
 
Current3,181,294540,824
1-30 days310,818—
31-60 days120,60421,455
61-90 days18,477—
91 days and over441,5089,021
4,072,701571,300

For product sales, the Company estimates the amount of consideration to which it expects to be entitled under provisional pricing arrangements. For the twelve months ended October 31, 2021, the fair value gain arising from changes in estimates was $805,789 (twelve months ended October 31, 2020: Nil).
An insignificant portion of the receivables relate to services revenue which are initially measured at fair value and subsequently at amortized cost. For the period ended October 31, 2021 and 2020, the Company has assessed an allowance for credit loss of $nil for service-related receivables based on its past experience, the credit ratings of its existing customers and economic trends.
October 31, 2021October 31, 2020
$$
Harmonized Sales Taxes receivable379,814274,998
Other receivables593,33143,931
973,145318,929