Posted on 30/07/26 09:14 am
You can write freely on Substack for quite a while without handing over a phone number. The platform is refreshingly light on friction when you are building an audience. But the moment you decide to turn on paid subscriptions, the dynamic shifts — and your personal number ends up in the middle of it.
Phone verification is not always required when you first create a Substack account. The trigger most writers do not see coming arrives mid-setup, when they are already excited about monetising their work: enabling paid subscriptions makes phone verification mandatory. The reason sits one layer deeper than Substack itself.
Substack uses Stripe as its payment processor, and Stripe requires verified personal details — including a phone number — to meet financial regulations. This ensures that only legitimate users can link bank accounts and receive payments, reducing the risk of bots and fraudulent activity. In short, a regulatory requirement for payment processors trickles down and becomes your problem as a creator.
Here is something many Substack writers discover only after the fact: the phone number you provide does not simply sit quietly in a database used for occasional login codes. It can surface in places you would never expect.
When you connect Stripe to your publication, Stripe notes that the customer support details you enter may be visible on payment statements, invoices, and receipts. That means a subscriber paying for your newsletter could see your personal mobile number on their credit card statement — not exactly the boundary you would want between a professional publication and your private life.
When you use your personal number, it becomes permanently linked to your email address, your Substack publication, and your Stripe records. For writers covering sensitive topics, working under a pen name, or simply valuing a clear line between their creative work and personal identity, this is a real concern rather than a theoretical one. It is also worth knowing about a second exposure point once your account is live: in your Stripe dashboard under Public details, there is a toggle labelled "Show phone number on receipts and invoices." If that toggle is purple, your number is visible to paying subscribers. Switching it to grey hides it — but the cleaner long-term fix is to use a dedicated virtual number in that field from the start, so nothing sensitive is ever there to hide.
The number of platforms holding your real phone number matters more than most people appreciate until something goes wrong. Leaked phone numbers increase the risk of SIM swapping, where attackers trick your mobile carrier into transferring your number to a device they control — allowing them to intercept SMS verification codes for your bank, email, or other accounts. If your real number is attached to your Substack and Stripe accounts, a platform-level security incident can quickly become a personal financial security incident. This is precisely why keeping your real number out of every non-essential verification flow matters, a point explored further in our post on why your real phone number is a risk every time you sign up.
The most common frustration creators run into is a verification rejection. Platforms using Stripe's KYC infrastructure tend to be stricter than a basic social media signup, because genuine financial compliance sits behind the verification step.
The key distinction that determines whether a number passes or fails is whether it is carrier-registered as a genuine mobile line, rather than an internet-based (VoIP) number. Services built entirely on VoIP infrastructure are often flagged because carrier data signals that the number is not a real mobile line. A non-VoIP, carrier-registered number — one that looks identical to a standard US or UK mobile at the network level — gives you the best chance of passing without an error message.
SMS Pin Verify provides non-VoIP, carrier-registered US and UK numbers built specifically to pass the kind of verification checks that trip up lower-quality virtual numbers. Whether you need a number for a single verification or want to rent one for up to 25 days to keep your Stripe account stable through any re-verification steps, the approach is straightforward: a real-looking number, used for the right purpose, with no personal details attached. Browse available numbers at SMS Pin Verify — per-use pricing starts from a few cents, and basic use requires no mandatory signup.
Many Substack creators run more than one publication — perhaps a personal newsletter alongside a niche-topic one, or a client project managed in parallel with their own writing. Each paid publication connected to Stripe needs verified account details, and using a single personal number across multiple monetised publications creates a web of dependencies. If your number changes, or if your carrier account develops a problem, every account tied to it is at risk.
We have written separately about this domino effect in our post on getting locked out of apps when your phone number changes, and the Substack-plus-Stripe combination is one of the more painful examples because payments are directly involved. A dedicated virtual number for each publication solves this cleanly: each account has its own verified contact detail, entirely separate from your personal number and from each other.
Journalists, whistleblower advocates, political commentators, and writers covering health or legal topics often choose Substack precisely because of its independence from large platform moderation. Many of these writers have a genuine operational-security reason to keep their phone number out of any linked database. For them, a virtual number is not just a convenience — it is a meaningful part of keeping their personal identity separate from their publication, regardless of what verification requirements the platform imposes.
Substack's phone verification requirement is not unusual or aggressive — it is a natural consequence of financial regulation flowing through Stripe. But that does not mean your personal mobile number needs to be the one that satisfies it. A carrier-registered virtual number passes the same checks, sits at arm's length from your personal identity, and keeps your primary number out of any platform that might one day experience a security incident, change its data-sharing policies, or simply display your number somewhere you would rather it not appear.
The decision to go paid on Substack is a good one for most creators. Just make sure the number you hand over to make it happen is one you deliberately chose — not one that quietly ties your real identity to every subscriber payment and every future platform audit.
