What telecom tower due diligence examines
A tower trades on a multiple of its tower cash flow: contracted tenant rent minus ground rent, the item Grant Thornton’s tower-valuation guidance calls a tower business’s primary operating cost. Both sides of that equation exist only in documents: a ground lease, a stack of tenant leases, and the amendments that changed both over decades. Tower due diligence verifies that the cash flow you are pricing is the cash flow the paper supports. “The Towerco space is quite specific. There’s a lot of niche expertise and knowledge that is required to truly understand,” MYX CEO Yavor Mihailov told Inside Towers in August 2026. Six areas concentrate most of the risk.
Lease chain integrity
The operative rent and term usually sit in the latest amendment, not the original lease. Diligence reconstructs the chain: base lease, every amendment in sequence, every assignment. A missing link in the chain is an unverifiable number in the model.
Revenue quality
Two leases with the same rent today can be worth very different amounts in year ten. Fixed-percentage uplifts, index-linked formulas, caps, collars and reset dates decide how contracted revenue grows. Diligence extracts the mechanism, then recomputes it.
Colocation and subletting rights
Upside assumes you can add tenants. Some ground leases permit colocation freely, some require landowner consent, and some give the landowner a share of colocation revenue. Each variant prices the same site differently.
Assignment and change of control
Some leases require landlord consent before the lease, or the entity holding it, changes hands. The transaction itself can be the trigger, and finding it late puts third parties on your closing timeline.
ROFR landmines
Rights of first refusal over the lease, the site or the underlying land can reprice or block a deal, and lease advisors note that consent and ROFR language is sometimes tucked into sublease or non-compete sections. Sampling misses exactly those clauses.
Ground versus rooftop risk
Ground sites tend to carry long terms and a single landowner. Rooftops add a building owner, access and structural obligations, shorter terms, and redevelopment risk. The two need different checks and different discounts.
The time problem: deal windows against document volume
Exclusivity windows are set in weeks. A portfolio brings thousands of documents; a large one, hundreds of thousands of pages. Reading everything with human reviewers does not fit, so most teams sample: the largest sites get read closely, the tail is priced on the seller’s database.
The database is not a safe substitute for the tail. “We have seen across different portfolios the accuracy of these legacy databases is under 65 percent,” Mihailov told Inside Towers. At that accuracy diligence is document work, and the ROFR and consent clauses above live in exactly the documents the sample skips.
The alternative is scale, not sampling. As reported in Inside Towers, MYX processed approximately 250,000 documents in under 48 hours during one engagement. “This is now possible at scale,” Mihailov said in the same article. Day to day, MYX Analyzer processes hundreds of documents overnight with enterprise batch processing: SharePoint and bulk folder import move the data room in without manual re-uploads, every batch run shows an upfront cost estimate, and 40+ language support covers cross-border portfolios.
How a raw data room becomes a defensible rent roll is covered in read the whole data room. For the field-level mechanics of tower leases, see cell tower lease abstraction; for the operating side after closing, see telecom towers.
Tower due diligence checklist
Fifteen checks that catch most of the value at risk in a tower transaction. There is no form in front of it; printing this page prints just the checklist.
- Reconstruct the lease chain Collect the base ground lease, every amendment and every assignment in sequence; confirm nothing referenced is missing from the data room.
- Confirm parties and notice details Check that the current landlord and tenant entities match the chain of assignments and that notice addresses are current.
- Verify term and runway Extract commencement, expiry, remaining renewal options and their notice windows; flag sites with short runway and no renewal rights.
- Tie rent to the latest operative document Take current rent, currency and payment frequency from the newest amendment, never from the base lease or the database.
- Reconcile rent against payments Compare documented rent with what is actually being invoiced and paid; unexplained gaps in either direction are findings.
- Extract escalation mechanics in full Record the type (fixed or index-linked), the named index, margins, caps, collars, compounding basis and the next escalation date.
- Recompute escalations Recalculate today’s rent from the base rent and the clause as written; a mismatch is either missed revenue or an overstated rent roll.
- Map colocation and subletting rights Establish whether new tenants are permitted, what consents are needed, and whether the landowner takes a revenue share.
- Pull assignment and change-of-control clauses List every consent the transaction itself will trigger, with notice periods and deadlines against the closing date.
- Hunt for ROFRs and purchase options Search the full chain, including amendments and side letters, for rights of first refusal or first offer over the lease or the land.
- List termination and relocation rights Capture early termination triggers, landlord redevelopment or relocation rights, and cure periods.
- Check exclusivity and use restrictions Note technology limits, interference clauses and radius restrictions that cap future tenancy revenue.
- Separate ground and rooftop populations Score rooftop sites separately for building-owner consents, access rights and structural obligations.
- Collect estoppels and default history Gather estoppel certificates, default notices, open disputes and holdover status for each site.
- Trace every model input to a page Require every number feeding the valuation to carry a document name and page reference a reviewer can open.
In MYX Analyzer each check becomes a column with its own extraction prompt, and the grid fills site by site; the Analyzer extracts 500+ data fields, of which these fifteen are the transaction core. AI lease abstraction shows how a single field is defined and reviewed.
Findings that hold up in the data room
A diligence finding is worth what it survives. Tell a seller their rent roll overstates escalated rent and the reply is a request for proof, not a price adjustment. In MYX Analyzer, every extracted value carries a confidence indicator (HIGH, MEDIUM or LOW) and a document reference to the page and section it came from. A finding arrives in the data room as a citation: this clause, this page, this computed figure.
Accuracy runs 94.7 % on internal evaluation sets, and the workflow is built for expert sign-off. Confidence is a triage signal: reviewers clear LOW values first, rerun any cell or row without reprocessing the table, and route the hardest fields to the MYX MAX tier. What reaches the investment committee is a number, its source page, and the reviewer who confirmed it.
Data rooms hold material under NDA. MYX is ISO 27001 certified, customer documents are never used to train AI models, and Security & GDPR covers document handling in detail.
Escalations: the highest-yield verification
If tower diligence has one check that pays for the rest, it is recomputing escalations. Apply each clause as written to its base rent, using official index values, and compare with the invoiced rent. As reported in Inside Towers, missed tenant revenue runs roughly $230 per site per year; in a transaction, the same gaps surface as rent-roll errors priced into the deal. Recomputed portfolio-wide, revenue quality stops being a judgment and becomes a number.
“We have a specific workflow for ground leases. We have a specific workflow for tenant leases.”
Yavor Mihailov, MYX CEO, in Inside Towers, August 2026
The escalation calculator recomputes index-linked uplifts from official index values, and rent calculation shows how an extracted clause becomes a payment schedule.
FAQ
What is telecom tower due diligence?
Telecom tower due diligence is the document-verification stage of a tower acquisition or financing. It reconstructs each site’s lease chain, verifies rent, term, escalation, colocation and consent provisions in the executed documents, and reconciles the result against the seller’s rent roll, so the price reflects what the contracts actually say.
Which documents does tower due diligence cover?
Ground leases, tenant leases and license agreements, amendments and assignments, estoppel certificates, consents, side letters, and site documents such as permits and drawings. The operative terms usually sit in the latest amendment rather than the base lease, which is why complete document chains matter more than any single file.
Why not rely on the seller’s site database?
Portfolio databases drift from the paper as amendments accumulate. As reported in Inside Towers, MYX has seen legacy database accuracy under 65 percent across different portfolios. Diligence that verifies terms against the executed documents catches what the database silently got wrong; diligence that samples the database inherits its errors.
Can AI read an entire tower data room inside a deal window?
Yes. As reported in Inside Towers, MYX processed approximately 250,000 documents in under 48 hours during one engagement. Day to day, enterprise batch processing reads hundreds of documents overnight, and every extracted value carries a confidence indicator (HIGH, MEDIUM or LOW) and a reference to the page it came from, so expert review concentrates where it is needed.
Run the next deal on the full document set
Upload sample leases from a live transaction, define the fifteen checks as fields, and review every extracted value against its source page.
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