I need opinions on how your institution defines lapsed donors (3 yrs? 5 yrs? 10 yrs?)

We consider a Lapsed donor someone whose last gift was in was within the last 10 fiscal years but not within the last 3 fiscal years.

We define a lapsed donor based on two sets of criteria:

1: When they last gave

2: How much they have given accumulatively

We set up this system as we could not apply a lapsed date to all donors as some had given £5000, whereas others had given several million.   

For example, an individual or organisation that has given over £1m will be active for 10 years, whereas an individual or organisation that has given £5000 will only be active for 3 years unless they give again. 

We have created five donor levels and have applied different sets of lapsed donor criteria to each level, which is maintained through queries.

I know that this is a complicated system, but this is a very complicated database and this system ensures that we can accurately pull off active/lapsed donors. 

Thanks

Charlotte