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Industry’s Fastest Residential Solar Letters
We deliver fast & accurate structural letters and PE stamps through advanced automation
- guaranteed or your money back.
Permit Faster & Spend Less!
first-time approval rating
years of experience
solar letter capacity per month
Our benefits
Zero AHJ Rejection Guarantee
Solar Letters leverages Castillo Engineering’s experience since 1998, which has an industry leading 99.9% first time approval rating. If our letter receives an AHJ rejection, we will gladly issue you a full credit.
Fastest Turnaround Guarantee
We pride ourselves on our advanced automation, as we know how important it is to receive your stamps within the hour. If you do not receive your letter by the next business day or less, you will receive a full credit.
Lowest Price Guarantee
We will match or beat any documented competitor price. We also offer volume discounts through our Permit Partner Program.
“The customer service provided by Solar Letters is exceptional. Their team is responsive and always ready to help support Titan Solar Power to permit our projects quickly.”
Dalton Garris
External Design Manager
Titan Solar Power
“The Solar Letters platform is a game-changer for LGCY! It has simplified the structural and electrical engineering process and increased our turn times on stamped projects!”
Ben Ogden
Manager, Design and Engineering
LGCY Power
ADT Solar is consistently impressed with the Solar Letters team's expertise. Their industry knowledge is clear in every interaction, and the quality is unmatched!"
Tanner Smith
Lead, PV Design
ADT Solar
Lowest price or price match guarantee
Best Price Guaranteed
Fastest Turnaround Guarantee
We pride ourselves on our speed, as we know how important it is to permit your project quickly.
Industry leading 99.9% first time approval rating
Zero AHJ Rejection Guarantee
Can handle up to 100,000 letters per month
Large Order Capacity
Dedicated team for each client; improves turnaround time
Elite Customer Service Experience
Following us on Linkedin lets you stay connected and receive all of our company news and updates
“The customer service provided by Solar Letters is exceptional. Their team is responsive and always ready to help support Titan Solar Power to permit our projects quickly.”
Dalton Garris
External Design Manager
Titan Solar Power
“The Solar Letters platform is a game-changer for LGCY! It has simplified the structural and electrical engineering process and increased our turn times on stamped projects!”
Ben Ogden
Manager, Design and Engineering
LGCY Power
ADT Solar is consistently impressed with the Solar Letters team's expertise. Their industry knowledge is clear in every interaction, and the quality is unmatched!"
Tanner Smith
Lead, PV Design
ADT Solar
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