Bucket Migration
Bucket Migration: Bucket migration is the movement of a delinquent account between DPD buckets over time — for example from SMA-0 to SMA-1. Measured as a roll rate, it shows what proportion of each bucket deteriorates, holds or cures, and is the earliest reliable signal of portfolio stress.
Why Bucket Migration matters in credit and collections
- A key KPI for collection agencies: high migration rates mean the collection strategy is failing.
- By analyzing migration rates, AI models can predict future Gross NPAs accurately.
- The primary goal of early collections is to achieve 'negative migration' or 'roll-back' to current status.
Reading roll rates and forward flow
For each bucket in each period you can compute three outcomes: the share that cures back to current, the share that stays in the same bucket, and the share that rolls forward into the next. The forward-flow rate from SMA-0 to SMA-1, and from SMA-2 to NPA, are the two most operationally useful numbers a collections team can track.
The value of roll rates is that they lead your NPA number by two to three months. If the SMA-0 to SMA-1 roll rate rises in March, that cohort reaches day 90 around June. A lender watching roll rates has a quarter of warning; a lender watching only GNPA finds out after provisioning is already required.
Roll rates also isolate where a collections process is actually failing. A healthy SMA-0 cure rate with a poor SMA-1 to SMA-2 roll rate is a very specific diagnosis — the digital layer works and the human escalation layer does not — and it points at a fixable operational problem rather than a vague 'collections' problem.
Regulatory basis
Bucket definitions follow the SMA and NPA classifications in RBI's IRAC norms, so roll rates computed on those buckets are directly comparable to regulatory asset-quality reporting and to peer disclosures.
Source: Reserve Bank of IndiaHow lenders use bucket migration
- Track forward-flow rates weekly by product, vintage and sourcing channel — a blended roll rate hides the failing segment.
- Treat a rising SMA-0 to SMA-1 roll rate as an early-warning trigger, not a collections statistic.
- Use bucket-level cure rates to decide where to spend contact capacity, and to justify channel cost per bucket.
- Compare roll rates across cohorts of the same seasoning, since a young book naturally rolls differently from a mature one.
Bucket Migration — frequently asked questions
What is the difference between bucket migration and roll rate?
Bucket migration describes the movement itself; roll rate is the metric that quantifies it, expressing the proportion of a bucket that moved forward, held or cured in a given period. In practice the terms are used interchangeably.
Why is bucket migration better than DPD as a management metric?
DPD tells you where an account is today. Bucket migration tells you the rate at which your portfolio is deteriorating, which is a leading indicator. It gives you two to three months of warning before the same deterioration appears in your NPA number.