This updated guide explains the full-block (left-aligned) business-letter format and practical layout rules for modern use. It recommends 1-inch margins for US Letter or A4, balanced page composition, and use of open punctuation unless an organization specifies otherwise. It also covers letterhead alignment for print and digital use and when to choose printed letters over email or PDF.
Why format still matters
Good layout makes business letters easy to read and professional. Even in 2025, when most correspondence is email or PDF, a well-formatted printed letter or downloadable PDF reflects on you and your organization.Full-block (Block) format - the layout
The simplest, most efficient format is the full-block (or Block) style. All text is left-aligned; do not indent paragraphs. Use single spacing inside paragraphs and one blank line between paragraphs.Example (US Letter or A4 paper):
Parker Morgan Finnigan
Lawyers
PO Box 2345
SYDNEY NSW 2000
October 29, 2025
Ms. Janette Jamieson
PO Box 34687
NORTH SYDNEY NSW 2005
Dear Ms. Jamieson:
Subject: Contract with Acme Finance Corporation
I refer to our previous correspondence requesting a copy of the contract between you and Acme Finance Corporation. If you do not provide a copy of the original contract, we will not be able to act on your behalf. We need the contract to assess your claims accurately and to question Acme Finance Corporation's legal staff.
Please send a copy at your earliest convenience so we can proceed.
Yours sincerely,
Parker Johannson
Principal Legal Consultant
Parker Morgan Finnigan
Margins, balance and paper sizes
Use 1-inch (2.54 cm) margins all around for US Letter (8.5 x 11 in) or A4 (210 x 297 mm). Keep the content visually balanced: avoid crowding the top of the page. A centered block of text with consistent left alignment looks tidy on both short and longer letters.Open punctuation
Open punctuation omits punctuation after the salutation and complimentary close (e.g., "Dear Ms. Jamieson" and "Yours sincerely"). It's common and acceptable in modern business letters, but follow your organization's house style if it prescribes closed punctuation (colons or commas).Designing letterheads for print and digital
Design letterheads with readable contact details and consistent alignment. If you left- or right-justify header elements, align the leftmost graphic/text edge 1 inch from the page edge to match the body text margin. A centered header works well because it doesn't force a left or right text flow.Include both postal and digital contact methods (email, phone, website). For digital delivery, provide a high-resolution header in the PDF to preserve branding.
When to use a printed letter vs. email or PDF
Use printed letters when a physical signature is required, for formal notices, or when mailing is expected. For routine correspondence, email or a PDF with the same full-block format is faster and environmentally friendlier.This article covers format basics. The next tutorial will break down the individual parts of a letter (date, inside address, subject line, salutation, body, closing and signature).