Form TM-48 no longer exists. It was the power of attorney form under the Trade Marks Rules, 2002, and those rules were replaced in 2017. If you have been told to file a TM-48, or you have found a TM-48 template online, the form you actually need is Form TM-M.
What TM-48 used to be
Under the old Trade Marks Rules, 2002, Form TM-48 was the authorisation you signed to let an advocate or a registered trademark agent act for you before the Registry. It was a standalone form with one job.
The Trade Marks Rules, 2017 replaced the old set of forms with a much smaller group, and the standalone power of attorney went with them. Rule 19 of the 2017 Rules now says it plainly: the authorisation of an agent for the purpose of section 145 shall be executed in Form TM-M.
Why people still search for it
Three reasons, and all of them are understandable.
Old templates are still circulating. A large number of TM-48 sample documents, blog posts and downloadable formats remain online, many of them written before 2017 and never updated. Some are still being handed out today.
The name stuck. TM-48 was in use for fifteen years. People who filed trademarks before 2017, and professionals who trained in that era, often still say TM-48 when they mean the power of attorney.
Some sources are simply wrong. It is not hard to find pages published recently that describe TM-48 as the current form under the 2017 Rules. It is not.
What happens if you file the old form
Filing a TM-48 today does not quietly pass. The Registry expects the authorisation on Form TM-M, and an application supported by the wrong form is treated as one without a valid authorisation on file.
In practice that usually surfaces at the formalities check, where the application is marked as deficient for want of a proper power of attorney. That is not fatal, but it costs you time you did not need to spend, and the correction has its own deadline.
What to file instead
Form TM-M is a multipurpose form. The same form covers several different requests, and the power of attorney is one of them, so when you file it you are selecting the relevant purpose rather than using a form dedicated to authorisation.
Two practical points. The authorisation should be signed by the applicant, not by the agent. And where the applicant is a company or an LLP, the person signing needs the authority to bind it, which is a question of board resolution or partnership authority rather than trademark law.
Stamping is a separate question from the form itself, and the stamp value for a power of attorney is governed by state stamp law rather than the Trade Marks Rules.
The short version
If a document, template or adviser refers to Form TM-48, treat that as a sign the source predates 2017. The current form is Form TM-M under Rule 19, and using it correctly the first time avoids an objection that is entirely avoidable.
If TM-48 is out of date, what else is?
TM-48 is rarely the only stale reference in an old template. The 2017 Rules collapsed a long list of numbered forms into a much shorter set, so if your paperwork mentions TM-48 it very likely mentions other retired forms too. The common replacements:
TM-1 (application for registration) is now TM-A.
TM-48 (authorisation of agent) is now TM-M.
TM-12 (renewal) is now TM-R.
TM-5 (notice of opposition) is now TM-O.
TM-16 (amendment or correction) is now part of TM-M.
Assignment and other post-registration changes are now made on TM-P, registered user entries on TM-U, and registration as a trademark agent on TM-G.
The pattern is that the 2017 Rules replaced numbers with letters, and several old single-purpose forms were folded into one multipurpose form. TM-M absorbed the largest share of them, which is why it now covers the power of attorney along with extensions of time, amendments and a number of other requests.
A note on filing online
Filing through the Registry's e-filing system reduces the risk of this mistake considerably, because the system presents the current forms and will not offer you a form that no longer exists. The old numbers survive mainly in offline templates, saved drafts and third-party formats that were never updated after 2017.
If you are working from a document someone gave you rather than from the Registry's own system, check the form references before you sign anything. A power of attorney executed on the wrong form is easy to fix but entirely avoidable.