The evidence has to outlive the claim by six years
The claim is money in the bank within a few weeks. The obligation it creates lasts years, and it is an obligation to produce evidence rather than to have been right.
Key takeaways
Keep the declaration, not a note that one existed.
Freeze the donation record as it was when claimed.
Store the reason for every exclusion as well as every inclusion.
Six years after the end of the accounting period, not six years from now.
Cancellation and correction are events to keep, not edits to make.
What an audit actually asks
Fig 1. Three inputs to an audit and three things it needs to see. The system’s job is that all three still exist and still line up.
Machine learning
Security & identity
Analytics
A flag is not evidence
The single most common shape of failure is a donor record with a Gift Aid box ticked and no document behind it. It is enough to build a claim from and not enough to defend one, and the gap between those two states is invisible until somebody asks.
So the declaration itself is kept: the scan, the web submission with its timestamp, or the written confirmation sent after a verbal declaration. It is a small file, there is one per donor rather than one per donation, and it is the cheapest thing in the system to store and the most expensive to be missing.
Six years, counted from the right place
Fig 2. Five stages, and the fourth is longer than people assume. The clock does not start when the money arrives.
Storage
Machine learning
Security & identity
Corrections are events
A donor cancels. A declaration turns out to have the wrong address. A donation is refunded. Each of these changes what should have been claimed, and each is a new fact with its own date rather than a reason to edit an old one.
Keeping them as events costs nothing and makes the difference between a system that can say this was correct when claimed and changed in March and one that can only say this is wrong now. The first is a conversation with HMRC. The second is a repayment.
The sentence the evidence has to be able to write
This donation of 40 pounds was received on 12 March.
It was matched to a donor whose declaration took effect on 3 February.
That declaration is attached, with the home address HMRC matches on.
It was claimed in the schedule submitted on 30 June, line 1,844.
The declaration was cancelled on 9 September, which is after this donation.
Where this ends
The system does not make the charity compliant, because compliance is a thing people do rather than a thing software has. What it does is make the compliant answer the cheap one: the declaration is already stored, the routing already has a reason against every donation, and the claim already froze its own inputs.
The next post prices it and the one after gives the service names, the tables and the IAM. The interesting thing about the cost is that almost none of it scales with donations, because the expensive step happens once per donor rather than once per gift.