MCD-300A Form – If you’re applying for an oversize/overweight (OS/OW) permit in Texas — especially an Annual Envelope Permit — you’ll likely need the MCD-300A Form, officially titled the Weight Supplement Sheet. This one-page document from the Texas Department of Motor Vehicles (TxDMV) provides critical maximum allowable axle and group weights to ensure your commercial vehicle stays compliant with state regulations.
In this SEO-optimized guide, we break down exactly what the MCD-300A is, who needs it, how to use it, and where to download the latest official PDF — all sourced directly from TxDMV.
What Is the MCD-300A Weight Supplement Sheet?
The MCD-300A (Rev. 08/19) is a supplemental reference and compliance form used in Texas motor carrier operations. It details the maximum allowable weights for steer axles, single axles, tandem axles, triple axles, trunnion axle groups, and quad axles — both on standard highways and load-zoned roads.
It is primarily associated with Annual Envelope Permits (and other OS/OW applications) to supplement weight data on your commercial vehicle registration or permit request. Vehicles may not exceed the maximum weight per axle, axle grouping, or gross weight listed on the permit.
Official form number: MCD-300A
Revision date: August 2019 (still the current version linked on TxDMV.gov as of 2026)
Page count: 1 page
Who Needs the MCD-300A Form?
You need the MCD-300A if you are:
- Applying for or renewing an Annual Oversize/Overweight Envelope Permit
- Operating commercial vehicles that may exceed standard legal weights (up to 120,000 lbs gross for envelope permits)
- Supplementing a weight certificate for registration or permitting
- Hauling non-divisible loads that require precise axle-weight calculations
It is not required for every vehicle registration but is standard for most annual OS/OW permit applications processed through the TxDMV Motor Carrier Division.
Key Maximum Allowable Weights on the MCD-300A
The form lists TxDMV-approved weight limits (minimum 12 feet between axle groups required):
Standard Highways
- Steer axle: 650 lbs × tire tread width × number of tires (example: 650 × 10.00 × 2 = 13,000 lbs)
- Triple (3) axle: 60,000 lbs total / 20,000 lbs per axle
- Tandem (2) axle: 46,000 lbs total / 23,000 lbs per axle
- Single axle: 25,000 lbs
- Trunnion axle group: 60,000 lbs total / 30,000 lbs per axle (8 tires/axle, min. 10 ft width)
Load-Zoned Roads (10% reduction required)
- Triple: 54,000 lbs / 18,000 lbs per axle
- Tandem: 41,400 lbs / 20,700 lbs per axle
- Single: 22,500 lbs
- Trunnion: 54,000 lbs / 27,000 lbs per axle
Quad (4) axle: Up to 70,000 lbs / 17,500 lbs per axle (or 63,000 lbs / 15,750 lbs on load-zoned roads)
Example Truck/Trailer Combinations (5-axle or 6-axle):
- 5-axle: 13,000 + 46,000 + 46,000 = 105,000 lbs (or 95,800 lbs on load-zoned roads)
- 6-axle: 13,000 + 46,000 + 60,000 = 119,000 lbs (or 108,400 lbs on load-zoned roads)
Unusual combinations are calculated case-by-case by TxDMV.
How to Use and Complete the MCD-300A Form?
The MCD-300A is largely a pre-filled reference sheet — you don’t fill out complex tables. Most applicants:
- Print the official PDF.
- Review the weight limits that apply to their vehicle configuration.
- Attach it (or reference the limits) when submitting your main permit application (e.g., MCD-301 series for Annual Envelope Permits).
- Ensure your actual axle spacings and weights match or stay under the listed maxima.
Pro tip: If your annual permit lists specific axle spacings, you must follow them exactly.
Submission: Include with your OS/OW permit application via TxDMV online portal, mail, or in-person at a Motor Carrier office. For questions, call (800) 299-1700 or email [email protected].
Download the Official MCD-300A PDF
Direct download (always use the official source):
https://www.txdmv.gov/sites/default/files/form_files/MCD-300a.pdf
This is the exact file hosted by TxDMV — 201 KB, printable, and up to date.
Important Regulations & Warnings
- Minimum 12 feet between axle groups.
- On load-zoned roads, reduce weights by 10%.
- Never exceed bridge posting limits or cross railroad tracks without caution.
- Night travel allowed only for overweight-only loads.
- Routing is the permittee’s responsibility.
- Vehicles must comply with the federal Bridge Gross Weight Formula where applicable.
Related Texas Permits That Use the MCD-300A
- Annual Oversize/Overweight Envelope Permit (MCD-301)
- General OS/OW permits
- Over Axle/Over Gross Weight Tolerance Permits
Full list of OS/OW forms: TxDMV OS/OW Permits Page.
Frequently Asked Questions (FAQ)
Is the MCD-300A required for every truck registration?
No — only when applying for weight-related OS/OW permits.
Can I submit the form electronically?
Yes — most TxDMV permit applications accept PDF uploads.
Has the form changed since 2019?
No newer revision is posted on TxDMV.gov as of 2026.
Where do I find axle weight calculator help?
Contact TxDMV Motor Carrier Division directly — they calculate unusual configurations case-by-case.
Final Thoughts
The MCD-300A Weight Supplement Sheet is your essential quick-reference tool for staying legal and avoiding costly fines on Texas highways. Whether you’re a fleet manager, owner-operator, or permit expediter, keeping the latest PDF handy will streamline your Annual Envelope Permit applications.
Ready to download? Grab the official MCD-300A PDF here and get your Texas OS/OW permit process started today:
https://www.txdmv.gov/sites/default/files/form_files/MCD-300a.pdf
For the most current permit requirements, always visit the official TxDMV Motor Carrier Division website or call their support line.
Sources: Official TxDMV website and form PDF (current as of March 2026).
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