--- title: Configure Unique Number Prefixes url: https://docs.maxio.com/configuration/maxio-core/account-user-settings/configure-unique-number-prefixes applies_to: Maxio Core updated: 2026-09-19 --- # Configure Unique Number Prefixes Add a prefix to the numbers Maxio generates, so a record's number says what kind of record it is at a glance. ## How generated numbers work Maxio assigns a number to a new Invoice, Customer, Contract, Transaction, or Invoice Line Item whenever you leave the required **Number** field blank. Each object type keeps its own counter, starting at 1 and rising by 1 for every record of that type: your first Transaction is 1, your second is 2, and so on. A number is never reused. Once a record is saved its number is spent, even if you later delete that record, and if the next number in line is already taken the counter skips it and moves on. Generated numbers are therefore always unique within a record type. ## Set a prefix Two prefixes sit in front of those counters, and both are set in Account Settings: - **Generated Number Prefix** - A single, shared prefix applied to Customers, Contracts, Transactions, and Invoice Line Items, and to Payments, Deposits, Subscriptions, and the Expenses records (Vendors, Vendor Contracts, Expenses, Bills, Bill Line Items, and Bill Payments). - **Generated Invoice Number Prefix** - Used exclusively for Invoices. You can run one prefix for every Invoice, or a separate prefix per Register if Maxio Support has enabled per-Register numbering for your account. Either prefix can be left *blank*. Any combination of letters, numbers, and symbols can be used for these prefixes, such as: - Annual - 800000 - EURO- - SegA- Spaces are not allowed in either prefix. The prefix is then concatenated with the value provided by the counter to create the full, unique record number. For example, if a *non-Invoice prefix* of **2023-** was set, you might have a Customer numbered **2023-**12, a Contract numbered **2023-**14, a Transaction numbered **2023-**30, and an Invoice Line Item numbered **2023-**84; all with the same prefix. Similarly, an Invoice with an *Invoice prefix* of **USD2023-** can be numbered **USD2023-**34. ## Including the object type in generated numbers You can also insert an identifier for the object type between the prefix and the counter, so a generated number reads `2026-CUSTOMER-1000` rather than `2026-1000`. This makes it obvious from the number alone which kind of record you are looking at. To turn this on, enable **Include Object Type in Generated Numbers** in Account Settings. Three identifier fields then appear, one per object type: | Field | Default identifier | | :--- | :--- | | Customer Number Type Identifier | `CUSTOMER` | | Contract Number Type Identifier | `CONTRACT` | | Transaction Number Type Identifier | `TRANSACTION` | All three are required once the setting is enabled, and none of them can contain spaces. The prefix and identifier together cannot exceed 236 characters, which leaves room for the counter value.