Investigation if submitting SA self assessment early

[HarryHowls]

Hi,

I fill in an SA every year and often have it ready by August or earlier! I force myself to wait until after October to file it as a friend once told me that if you file really early then they are more likely to investigate your taxes on account of having more available time!

Is that true? Or was it ever?

[bd6759]

Not true. The enquiry window is 12 months from the date it is filed.

[someone]

What I was told by my accountant, albeit over 20 years ago now is that HMRC had various (undisclosed) tests that flagged returns as worthy of investigation. They then added a random selection to those making it up to 10% (I think although that sounds high to me)

Most of the investigations would be along the lines of 'please explain how you arrived at the figure in box B123' and provided the answer was reasonable the investigation would be closed. But if the answer was vague or evasive then an investigation into the entire return would be started.

At least one person I know who had an investigation that eventually took three years to close (with no tax due but a reprimand for inadequate record keeping that had to be resolved for the future) had their investigation start much like that with a simple question that ballooned.

[bd6759]

20 years ago saw the introduction of self assesment. Tax return data was captured from that point enabling HMRC to build a profile over years, usually based in business economic tests.

It became much more sophisticated from 2009, when their new system drew information from all their information sources:

https://www.taxation.co.uk/Articles/201 ... -connected