How do I actually build a provision matrix for doubtful debts by aging bucket?

A provision matrix is the simplified method IFRS 9 allows for calculating expected credit loss on trade receivables, instead of tracking every customer individually. The first step: split client balances into aging buckets (current, 30-60 days, 60-90 days, over 90 days), then calculate the actual historical loss rate for each bucket from one or two prior years of data — what percentage of balances in each bucket ultimately went uncollected.

Those historical rates then need adjusting for reasonable, supportable forward-looking factors — an expected slowdown in the sector, or heavy concentration in a small number of clients. The result is a different provision rate per aging bucket, rising the further a receivable is overdue, applied to each bucket's balance every month or quarter. RASEEKH builds a provision matrix tailored to each client's actual data, not a generic rate borrowed from somewhere else.