Codes and sign-in links
Mailbox and phone verification terms describe how a service checks access to an email address or number, and how an account can be recovered later. For a media buyer setting up a working account, the key question is not only whether a code arrives now, but whether the contact method will remain accessible and under the account holder’s control.
OTP (one-time password). An OTP is a temporary credential sent or generated for a sign-in or verification step. It is intended for a particular use rather than as a permanent password, though the exact process depends on the service. For an account on a platform such as Google or Meta, understand who can receive the OTP and how access will be maintained before relying on a mailbox or number.
Verification code. A verification code is a sequence of characters or digits used to confirm that someone can access a particular contact method or complete a requested action. It may arrive by email, text message, or another channel. Registrants should distinguish it from the account password and keep it private; a seller should also clarify whether any setup process depends on a contact method the buyer will not control.
Magic link. A magic link is a sign-in or confirmation link delivered through a message, allowing the recipient to continue without entering a conventional password at that step. It is still a sensitive credential: anyone who can open the message may be able to use the link while it remains valid. Check that the mailbox is accessible and under your control before using a link to establish account access.
Recovery contacts
Recovery address. A recovery address is an email address associated with an account so it can be used for account recovery or important security communications. It is different from the account’s primary mailbox, although a service may allow one address to serve more than one role. When accepting an account, confirm which address is attached and whether you can access it; an inaccessible recovery route can make later account management difficult.
Recovery number. A recovery number is a phone number associated with an account for recovery or security-related communication. It is not necessarily the same as the number used during initial registration. Before relying on it, establish who controls the number and whether that control can continue over time. If the number belongs to another person or provider, the account may depend on their continued cooperation.
Backup code. A backup code is a stored credential intended as an alternative way to access an account when a usual sign-in or verification method is unavailable. Services differ in how they issue and accept such codes, so follow the instructions for the specific account. Keep any provided codes private and in a secure place, and verify that the account holder—not a seller or former operator—can retrieve and protect them.
Mailbox arrangements
Alias. An email alias is an alternate address that routes messages to another mailbox, rather than necessarily being a separate mailbox with its own independent inbox. The arrangement can help organize communications, but the destination mailbox remains important: whoever controls it may be able to read messages sent to the alias. For a registration, document which address is attached to the account and make sure the routing can be maintained by the responsible account holder.
Catch-all mailbox. A catch-all mailbox is configured to receive mail sent to addresses at a domain even when the specific address is not separately set up as an individual mailbox. This can make it harder to tell whether an address is dedicated to one account or shares a broader mail destination. Before using such an address, establish who controls the domain and mailbox, who can read incoming messages, and whether access can be separated if account ownership changes.
Phone-number types
Shared number. A shared number is a phone number used by more than one person or account, rather than being dedicated to one registrant. Messages may be visible to other users or difficult to attribute to a particular account. That makes it a poor basis for ongoing account control when the service expects the number to remain reachable. Ask whether the number is exclusive and who can receive future messages before accepting an account that depends on it.
Virtual number. A virtual number is provided through a service or software-based system rather than being tied in the usual way to a physical SIM in a handset. Its availability and message handling depend on the provider and the specific service. A registrant should check whether the number supports the communication needed for the account and whether access can be retained. Do not assume that a number that works for one message will remain available for future recovery.
Rental number. A rental number is made available for use over a limited service arrangement, rather than being held as a permanent personal number. The provider controls the number and may determine how long it can be used and how incoming messages are handled. This matters because an account can outlast the rental arrangement: if recovery later depends on that number, the account holder may no longer be able to receive a message.
Physical SIM. A physical SIM is a removable subscriber identity module used in a compatible mobile device to connect a phone number to a mobile service. Control of the SIM and the associated service can affect who receives calls or text messages. If a SIM is part of an account handover, clarify who holds it, who can manage the service, and whether the number is intended to remain with the account holder rather than another party.
Number availability and timing
Activation window. An activation window is the period during which a number or service is available for a particular activation or verification process. The provider or platform may define the relevant timing, so the term alone does not establish how long access lasts. For a registrant, the practical concern is whether the window covers the required task and what happens afterward. Do not treat temporary activation access as a lasting recovery method.
Number pool. A number pool is a collection of phone numbers made available through a provider or system, often for assignment or use as needed. A number drawn from a pool may not be reserved for one person indefinitely. Before relying on a pooled number for a continuing account, find out whether it is dedicated, how future messages are handled, and whether the same number remains under the registrant’s control. Temporary availability is not the same as durable access.
Message delivery
Sender ID. A sender ID is the label or identifier shown as the apparent sender of a message, instead of, or alongside, a phone number. Its display and handling can vary by messaging route, device, and service. For someone checking a registration message, the sender label can help identify a communication, but it does not by itself prove that the message is genuine. Use the platform’s own sign-in or account process rather than trusting an unfamiliar message solely because of its displayed name.
Delivery delay. A delivery delay is the time between a message being sent and its arrival, which can occur with email or text messages for reasons outside the recipient’s control. A delayed verification message can lead someone to request another message or use an alternative route, but repeated attempts may create confusion about which message is current. Check the service’s instructions, avoid sharing codes, and make sure the contact method is one you can access reliably.
Checking an account handover
When a seller provides an account, treat its mailbox and number arrangements as part of the product’s access and recovery setup, not as incidental details. Ask for a written description of the attached addresses and numbers, who controls them, what credentials or recovery methods are included, and which steps remain for the buyer. Do not accept assurances that depend on an undisclosed third party being available later.
Access under your control. This means the account’s relevant sign-in and recovery methods can be reached and managed by the responsible account holder, rather than remaining dependent on a seller, shared inbox, or temporary number. Control should include practical access to the contact methods and the ability to protect them. Check the account’s own settings and follow the platform’s terms; do not attempt to conceal ownership or work around verification requirements.
Handover record. A handover record is a written summary of what is being transferred and what remains outside the buyer’s control. It can identify the primary mailbox, recovery address, recovery number, available backup methods, and any limitations such as a temporary number arrangement. This helps the registrant assess whether the account is suitable for its intended work and spot unresolved dependencies before putting time into setup or campaign preparation.
Choosing a workable setup
A contact method that receives one message is not automatically suitable for ongoing use. Consider whether the account type and its recovery options fit the intended job, whether the relevant mailbox or number will remain accessible, and whether the arrangement complies with the platform’s terms. If access relies on a shared or rented resource, document that limitation rather than treating it as a permanent feature.
The glossary terms point to a practical distinction: verification is a moment in setup, while account control is an ongoing responsibility. A sound handover makes clear how both are handled, without relying on hidden access, another person’s goodwill, or a temporary channel that may disappear.