Aftermarket Domain Due Diligence Checklist (Age, RDAP, DNS, and Typos)

Marketplace listings move fast. Screenshots lie. “Traffic” charts lie harder. If you are spending real money on a domain someone else already owned, you need a checklist that survives a skeptical cofounder and a busy registrar support line.

This is the BenOpt-flavored version: registry timestamps, DNS reality, typo exposure, and cart confirmation. Not legal advice. Not a promise of SEO outcomes. Just the homework that prevents obvious regrets.

Quick answer

Before you pay:

Confirm registry status and dates with RDAP lookup.
Measure age and expiry with the domain age calculator.
Inspect DNS with DNS record lookup and a quick subdomain explorer pass.
Scan typos with the typosquat generator.
Verify price and transfer path in your registrar cart.

Section A: registry truth (RDAP)

RDAP returns registered for the exact apex string you intend to buy
Registrar name matches listing or broker disclosure
Expiry event copied into notes (expiry guide)
Status URIs reviewed (status codes guide)
No redemption or pending delete language unless you planned for it
Nameservers recognized (parking vs your future host)

If RDAP is unsupported for the TLD, pause and use the registry’s native lookup.

Section B: age and history claims

Creation event captured or missingness documented
Age calculator output saved when timestamps exist
Seller claims compared to RDAP creation, not just archive screenshots
Recent last changed event noted if transfer just happened

Read how to check domain age before buying for narrative detail.

Section C: DNS and public attack surface

Apex A/AAAA/MX/TXT/NS reviewed in DNS lookup
www host checked separately
Subdomain explorer run for obvious infra leaks
Unexpected mail or SPF records flagged for security review

Quiet DNS plus registered RDAP is common. Note it explicitly instead of calling it “empty.”

See why no website but RDAP registered.

Section D: typos and brand confusion

Typosquat variants generated for the label you will announce
DNS scan run on variants
Top taken typos documented (competitor risk)
Defensive registration plan chosen (typos vs defensive registration)

Section E: availability double-check (DNS + RDAP)

Even in aftermarket buys, run the two-step logic:

Bulk or single DNS check recorded
RDAP still shows registered to the seller’s story
You are not confusing “available to register fresh” with “available to buy from owner”

Workflow: DNS and RDAP together.

Section F: money and transfer mechanics

Registrar cart shows expected price (no surprise premium tier)
Transfer lock status understood
Auth code or broker escrow path documented
Renewal cost for years 2-5 estimated

BenOpt does not process payments. This step is entirely on your registrar.

Red flags that should slow you down

Seller refuses RDAP screenshots or registry references
Creation date missing while listing screams “15 year aged domain”
Mail records suggest bulk spam history
Subdomain scan shows public staging with open admin paths
Expiry within days unless you specialize in drop catching

Minimum viable diligence (15 minutes)

When budget is tight, do not skip everything. Do this:

RDAP lookup (3 min)
Age calculator if creation exists (2 min)
DNS lookup on apex (3 min)
Typosquat generator plus DNS scan (5 min)
Registrar cart price (2 min)

You will miss deep security history, but you will avoid the worst “wrong name” mistakes.

Full diligence (same day, deeper)

Add:

Subdomain explorer on production targets
Manual archive review for spam eras
Broker escrow verification
Trademark counsel for US or EU launches
Email to current owner with RDAP facts attached

Use the full checklist sections above as your outline.

Post-purchase cleanup

After transfer completes:

RDAP shows your registrar
DNS pointed at your stack
Old MX removed if unused
Typos you bought now 301 correctly
Auto-renew enabled with a card that will not expire silently

Diligence does not end at payment. It ends when customers see the right site.

Broker escrow-specific notes

When money sits in escrow, agree which party runs RDAP on the day of transfer. A name can change state between offer and closing. Refresh lookups the morning funds release.

Attach RDAP screenshots or exported notes to escrow emails so everyone references the same registrar string.

FAQ

Is this checklist enough for trademark clearance?

No. Hire counsel when brands matter.

Should I use Wayback Machine?

Optional but useful. It is not registry proof.

Can BenOpt replace a broker’s audit?

No. Brokers add negotiation and escrow. We add public signals.

How long should I keep diligence notes?

Keep them until transfer completes and DNS points at your stack. Attach the spreadsheet to your internal asset inventory.

Should I rerun the checklist after a price drop?

Yes. A lower price does not fix a bad registry status or spammy DNS history.

What to do next

Duplicate this checklist into your notes app. Run the linked tools once per candidate domain. Keep a single spreadsheet with columns for RDAP registrar, expiry, DNS summary, typo count, and cart price.

When you are choosing among fresh registrations instead of aftermarket names, start with how to check domain availability in bulk.

BenOpt gives you fast public data. Your signature on the wire still means you accepted the risk.