Maximum 365 extension?

[My1dadmin]

Hello all, I have an office enterprise e3 account with 3 years remaining on the subscription. I am attempting to increase this timeframe as I have an unused license key and I was under the impression the max extension was up to 5 years but whenever I plug this code in the error message is that I should open a new account as the added time would put me over the max limit. The code is for one year. Does office365 enterprise have a different max timeframe than the other office 365 products? Thanks

[#2]

@My1dadmin 

I would strongly suggest to contact MIcrosoft 365 Commerce & Billing Team for this as it completely depends on the backend policy for acceptance or renewal of your subscription or the associated code if it is not punching on an existing subscription already. 

https://docs.microsoft.com/en-us/office365/admin/contact-support-for-business-products?view=o365-wor... 

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Admins, have your account details ready when you call.

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