Renew Quicken subscription

No long "renew", you "subscribe".

You can **renew** your membership/subscription.

It says so right on the page you cited.

As to the OP question:

How long can I extend my membership plan? A membership can only be extended in the last six months of a subscription term. Therefore, multiple terms cannot be purchased and used at once to extend a membership. Retail purchases: Activation codes expire 24 months after being generated.

I think you should do some online shopping.

You don't have to purchase Quicken software from Quicken, Inc. Amazon, Best Buy, Office Depot and Target (and likely more) have Quicken for sale. Some of those retailers used to offer purchases of subscriptions longer than one year.

I see Quicken for sale - for different prices (and possibly different term lengths) - at the afore mentioned retailers. I assume you could purchase a renewal from them for the product you first bought from them.

I believe at one time, you could purchase a renewal from any available seller, usable regardless of where you purchased the original product. I don't know if that is still true.

I may have misunderstood the intent of the question. Do you remember if you could 'renew' the "Please note that while Quicken is now a subscription product" for 2 years previously, then?