The Up API's persistent transaction UUIDs are a fantastic improvement over other banks' APIs. But the API doesn't expose other identifiers that Up sometimes uses for transactions.

The most important one is the FITID in OFX exports from the Android app, which seems to be an institutionally-unique sequential integer. That it is actually unique (as required by the format) is a great benefit over the OFX exports provided by most Australian banks, but it would be lovely if I could correlate transactions incrementally imported from the API with those from month-end OFX exports.

The only ID exposed in the Android app is the "payment ID", though given the lower rate at which it's incrementing I guess normal card etc. transactions might not have one of these at all.

The Android app exposes the initiator-supplied freeform NPP end-to-end ID (as "Reference ID"), but the API doesn't provide this information. Some other institutions also expose the NPP transaction ID, the 35 character string starting with the originating institution's SWIFT ID, a date, and then (at least in Up's case) an incrementing integer, which is useful for correlating even between different people or banks. I gather that there are limits to the NPP metadata that you can expose, but the transaction IDs don't seem to contain any PII and are shown by other banks.