You did not indicate what you want to post in July.  Do you want to post the payment in July and have your records show you did not take the cheque to the bank until Aug?  That kind of thing is normal when you write cheques and mail them.

Or did you want to post a purchase invoice in July and then just show the payment in August?  Again, also normal.

Or did you pay by having the bank take the money directly out your account without printing a cheque.

If the latter, then posting the payment in July is not reality and you should stick with reality as much as possible.

It won't "cause problems" no matter when you post whatever it is you are posting, unless you get audited and the CRA does not like what you did or if the way you post causes problems determining what happened and what you owe in the future.

For my business and all the clients we do bookkeeping for, the purchase invoice is posted with a date of the last day of the period (in your case June 30) and the payment is posted whenever the cheque/bank transfer/withdrawal is done.

Hi tdfwice,

From my point of view,  if you made the payment in Aug 4, you should use this date as your payment date.  

I cannot think of any serious problem posting the payment using the actual date.  

To the best of my understanding, if your GST remittance period is from April to June, you should pay it no later than July 31.  Late payment is all I can think of.

Hope this helps.  

I usually post the GST amounts by using a payable invoice as of the end of the period, then record the payment like any other payable, on the cheque or EFT date.  

This makes it more clear when reviewing the GST account, that the amount owing as of June, was paid August 4.

If an adjustment, reversal, or correction that affects GST is made after the June return is filed, even if it's August 4, it's easy to see on a G/L report (sorted by transaction) up to the end of June.