I'm in the U.S. I pay every year on January 15, (cap. gains + DIVs + interest).
I believe the rule is you have to prepay on Jan 15, 90% of what you estimate your final tax bill for the year. 1040 EST (Estimate)
I have already filed mine for 2021. My state already deposited their check, FEDs, not yet.
I always print off the cancelled checks and include it with my final 1040.
There is a short formula to determine who has to file the 1040 EST.
Penalties if you should, but you don't.
I have a CPA prepare all my taxes.
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I have read the the IRS has huge numbers of filers who are in arrears on cap gains.
Seems these are filers made some gains, but then quickly lost them.
That's probably the logic behind the 1040 EST filed on January 15.
Hope that helps.