After offering the interesting trade-in program last month, it looks like HTC wants to make sure that they have all bases covered.

To recall, the trade-in program calls for existing iPhone owners to trade in the old iPhone 6 or 6S for a brand new HTC One A9. 

Seeing that the ploy did wonders, HTC is giving folks who missed out another chance at getting the HTC One A9 by extending the promo until Jan. 7, 2016.

The promotional gimmick helped HTC hit a record 731% increase in sales for the company, something that Androidandme.com cited. Worth noting as well was that 10% of the folks who availed of the promo were former iPhone owners and new users.

The devices that HTC entertained include the iPhone 6, 6S, 6 Plus, and 6S Plus. But the trade-in program is not limited to iPhones only.

In fact, other brands such like Samsung and LG can also trade in their units, although there could be cash-outs to cover the differences.

For folks who trade in their Samsung Galaxy S6 or S6 Edge, customers will get a $200 credit with the difference to be covered by the interested buyer.

On the other hand, owners of the LG G3 or G4 will get a $100 credit with the balance the only thing that needs to be covered.

For those who are not yet familiar with the HTC One A9, this is a mid-range device that comes in a super-thin metal frame. It sports a 5.0-inch AMOLED screen and runs on a Qualcomm Snapdragon 617 quad-core processor clocked at 1.5 GHz.

It is backed by 2 to 3 GB of RAM and offers 16/ 32 GB of internal storage. It also features a 13-megapixel main camera, a 4-megapixel front-facing shooter and relies on a 2,150 mAh battery. It runs on Android 6.0 Marshmallow out of the box.