Trademarks (registered, applied for, or even non-registered) require that you can prove that you're still using the mark.
And here is why.
Anybody can request that your trademark be canceled if you have not been using your trademark for 3 years consecutively. And many big brands lost their trademarks after they either changed their trademark or if they stopped being on the market with a particular trademark.
So you have to be very, very careful not to lose the trademark.
But it's even more disappointing when you'd lose your trademark that you have been using but you don't have any evidence, any proof that you have been continuously using the brand.
So what you want to do is make sure that you keep a copy of all your business cards, make sure that you keep your invoices, make sure you keep snapshots of your website. Use Archive.org to do manual snapshots of your website on a particular date. Make sure that you have something that, if shown to a judge, would establish that you have been using this brand for all of the products and services listed in your trademark application or registration.
I hope this helps.
Disclaimer: Please note that this post and this video are not and are not intended as legal advice. Your situation may be different from the facts assumed in this post or video. Your reading this post or watching this video does not create a lawyer-client relationship between you and Trademark Factory International Inc., and you should not rely on this post or this video as the only source of information to make important decisions about your intellectual property.