noun which may take the genitive case particle 'no', na-adjective, noun
separate; additional; special or another
Describes something arranged or treated separately from the main item, often as an additional fee, procedure, contract, or arrangement. The nuance of "special" here is usually "separately provided," not "extraordinary." Typically used as 別途の or directly before nouns such as 別途料金.
A separate application is required to use this service.
A separate fee is charged in addition to the product price.
Adverbial use meaning that something is handled, paid, sent, discussed, or announced separately. Common in businesslike or official wording.
We will inform you of the details separately.
Transportation expenses will be paid separately.
Shipping costs an additional fee.
We will discuss the fee separately.
We will send the detailed materials separately.
We will notify you of any changes separately.
追加 means an addition or supplement itself, whereas 別途 emphasizes that something is kept apart from the main matter, which often results in an additional item.
個別 focuses on treating each item or person individually, while 別途 focuses on handling something apart from the main arrangement, often as an extra fee or notice.
別に can mean "separately" like 別途, but it is also very commonly used to mean "not particularly," so 別途 is clearer when you specifically mean a formal separate arrangement or charge.
別途 is an adverb meaning 'separately/additionally' (about procedure), while 別物 is a noun meaning 'a different thing' (about category), so learners often confuse them because both start with 別.
A Sino-Japanese compound of 別, "separate," and 途, "way" or "course." The literal idea is a separate way or course, extended to separate handling, separate arrangements, or additional charges.