Huge discrepancies in spend between API and UI

[CuriousWorld]

Hi all,
I was trying to pulling spend from API for each campaign. I have a data ranging from Jan 1st 2017 to Mar 13th 2017. When comparing with the data from UI, the spend of some Campaigns pulled from API are matched and some campaigns are not. I attach two files from different data resources and label all not-matched campaigns in red color below. Could you give me some advices about that? Thanks.

[JBabichJapan]

The most common reason for discrepancy in spend is not including all of the placements where the ad was served when you collect stats (PUBLISHER_NETWORK refers to running ads on Twitter Audience Platform (https://business.twitter.com/en/help/campaign-setup/twitter-audience-platform.html)

I would recommend to limit check to a single Ad Group and see if you can work your way back upwards from there, checking 1 day first then multiple days. If you cannot solve the issue feel free to post again but we are not tracking any issues around this and UI and API are powered by the same backend so it should be possible to get the numbers to line up.

Thanks,

John