Transferring 40 domains between registrars — checklist?

Hey guys, planning to move ~40 domains from one registrar to another. Doing it for better margins on renewals + the new panel has API access for my billing system.

Never done a bulk transfer this big before. Any leads on what I should watch out for? I know about the 60-day lock after transfer but anything else? 🙏

Got a mix of.com.net.org and a couple ccTLDs. Recieved quotes from a few places, saving roughly $3.50/domain/year so its decent money at this volume.

Before you touch a single auth code, drop your TTLs to 300 seconds across every zone. For what it's worth, I've seen bulk transfers go sideways because someone forgot their SPF record was hardcoded at 86400 and they spent 48 hours bouncing off blocklists after the glue changed.

Your DKIM selectors will survive if the destination registrar supports the same key format, but verify this. Some panels silently truncate 2048-bit RSA keys to 1024. DMARC policies at p=none will mask this failure until you get delisted.

Also: check if any of those 40 domains are on URIBL or Spamhaus DBL right now. Transferring a domain with existing reputation damage just locks the problem in at the new registrar. Clean first, move second.