Business thank-you letter examples and format: 7 letters to customers, clients, vendors and partners

A business thank-you letter is one typed page in block format. From the top: your letterhead or address, the date, the reader's name and address, "Dear Ms. Alvarez:", three short paragraphs (the thanks, one specific detail, a look ahead), a closing such as "Sincerely," your handwritten signature and your typed name. The format and seven full letters you can adapt are below.

The letters are for a customer, a long-standing client, a supplier, a referral partner, a meeting, a lender and a speaker. There is also a plain rule for when a card or an email does the job better.

What is the format of a business thank-you letter?

Use block format: every line starts at the left margin, with a blank line between parts. The order is your letterhead or address, the date, the reader's name and address, the salutation, the body, the closing, your signature and your typed name. Keep it to one page. The writing centers at Purdue University and George Mason University both teach this layout.

The parts in order:

1. Letterhead or your address. Purdue's Online Writing Lab says the sender's address is usually part of the letterhead. With no letterhead, type your street address, city and zip code one line above the date (Purdue OWL).
2. The date. Write out the month, day and year: "October 5, 2026". Purdue places it two inches from the top of the page.
3. The reader's name and address. Their name and title, the company, then the street address. It starts one line below the date and sits against the left margin.
4. The salutation. "Dear Ms. Alvarez:" with a colon after the name. If you are on first-name terms, Purdue says the first name alone is acceptable: "Dear Dana:".
5. The opening thanks. Say thank you in the first sentence, and say what for.
6. The specific detail. One thing they did, and what it changed for you.
7. A look ahead. The next time you will work together, meet or be in touch.
8. The closing. "Sincerely," or "With thanks,". Capitalize only the first word and put a comma after it.
9. Your signature and typed name. Purdue leaves four lines between the closing and your typed name. That gap is where you sign by hand.

Two more rules. Purdue names Times New Roman at size 12 as the generally accepted font, and says Arial works too. And George Mason's guide says to limit a business letter to one single-spaced page (George Mason University Writing Center).

Here is how that looks on the page. If you enclose anything, Purdue says to type "Enclosures" below the closing.

Harbor & Pine Catering
214 Dock Street
Portland, ME 04101

October 5, 2026

Ms. Dana Alvarez
Office Manager
Brightwater Dental Group
88 Elm Street
Portland, ME 04102

Dear Ms. Alvarez:

Thank you for choosing us for the lunch at
your annual staff day on September 26.

Your team sent the final headcount a week
early and told us about two allergies by
name. That is why nothing ran short and
nobody went without.

I will call in March about your spring open
day. Until then, the recipe for the lemon
tart is enclosed, as promised.

Sincerely,

(sign here by hand)

Maya Chen
Owner

Enclosure

What should a business thank-you letter say?

Three short paragraphs. The first says thank you and names what for. The second gives one specific detail: what they did and what it changed. The third looks ahead to the next job, meeting or call. That is all it needs. Leave out the sales pitch, the company history and any request.

Purdue gives the same shape for any business letter: a friendly opening and the main point first, the reasons next, and a last paragraph that restates the purpose. It also says being concise matters a great deal.

The specific detail is what makes the letter yours. If a line would fit in a letter to any other reader, rewrite it.

Do not worry that it will sound stiff or over the top. In a series of four experiments, Amit Kumar and Nicholas Epley found that people who wrote letters of thanks underestimated how positive and how surprised the readers would feel, and overestimated how awkward it would be (University of Chicago News).

When is a letter better than a card or an email?

Send a letter when the thanks is formal, long, or likely to be kept on file: a year of work, a large contract, a loan, a speaker. Send a handwritten card for a purchase, a referral or a small favor. Send an email when speed matters, such as the day of a meeting. Often the best answer is an email now and paper later.

Email is fast, but it is crowded. Microsoft's Work Trend Index, which draws on Microsoft 365 usage data, found that the average worker receives 117 emails a day, and most are skimmed in under 60 seconds (Microsoft WorkLab). A thank-you in that pile is easy to miss.

Paper has less to compete with. In a 2015 Gallup poll of 1,010 US adults, 41 per cent said they look forward to checking the mailbox each day, and over 90 per cent said they react positively to personal letters and cards (Gallup).

If the thanks is short and personal, it belongs on a card. Our guides to thank-you notes for business and small business thank-you messages to customers have messages sized for one.

Business thank-you letter examples

Each letter below starts at the salutation. Put your letterhead, the date and the reader's address above it. The companies and people are made up. Change the second paragraph to something true, or the letter will not work.

To a customer after a project or a large order

Dear Mr. Okonkwo:

Thank you for choosing Kestrel Print for your new menus and signs. It was our biggest job of the summer.

You approved every proof within a day, which is rare. Because of that, everything was on the tables two days before your reopening, not the night before.

I will stop by next month to see how the outdoor boards are holding up in the weather. If a corner lifts before then, call me directly.

Sincerely,

Priya Raman
Owner, Kestrel Print

For a home service job, a short card works better: see our contractor thank-you letters to customers. For online orders, see ecommerce thank-you cards after purchase.

To a client after a year of work

Dear Elena:

Thank you for our first full year of working together. Twelve months ago we were sorting two years of receipts in your back office. This month your books closed in three days.

You made that possible. You sent every statement on the first of the month without being asked, and you asked hard questions whenever a number looked wrong.

I would like to sit down in January and plan the year ahead, including the second shop. I will send some dates next week.

With thanks,

Marcus Bell
Bell & Hart Bookkeeping

To a vendor or supplier

Suppliers hear from customers when something is late, and rarely when it goes right. A letter gives your contact something to show a manager.

Dear Mr. Lindqvist:

Thank you for the Saturday delivery on September 19. I know your trucks do not usually run on weekends.

Our flour order was short through our own mistake, and we had three wedding cakes due on Sunday. Your driver was at our door by 7 a.m. All three cakes went out on time.

We have fixed how we count stock, so I hope not to ask again. We will place our holiday order with you in the first week of November.

Sincerely,

Rosa Delgado
Owner, Delgado's Bakery

To a partner after a referral

Referrals often come from people who have never been your client. In a Hinge Research Institute study of 523 professional services firms, 81.5 per cent had received a referral from someone who was not a former client (Hinge Research Institute).

Dear Anita:

Thank you for introducing us to Tom Reyes at Reyes Family Dental. We met on Tuesday, and we start moving his office to the new system next month.

You put your own name behind ours when you made that call. We know that, and we will look after his practice the way you look after his accounts.

I will let you know how the move goes. If a client of ours ever needs a good accountant, yours is the first name we give.

With gratitude,

Sam Whitaker
Whitaker IT Services

Only say the person became a client if they have agreed to that. Our accountant referral thank-you notes cover what you can say.

After a meeting

Send a short email the same day. Follow with a letter when the meeting was formal.

Dear Ms. Tanaka:

Thank you for meeting with me on Thursday. I know the end of a quarter is a busy time for a purchasing team.

Your point about delivery windows was the most useful thing I heard all week. We had planned around weekly drops. You need them twice a week in summer, and I had not understood why until you showed me the loading dock schedule.

I will send a revised plan by October 16, built around twice-weekly delivery.

Sincerely,

Daniel Osei
Sales Director, Greenline Produce

Once the deal is signed, see our thank-you note to a client after closing a deal. For the steps in between, see handwritten notes in sales.

To a lender or an investor

Asking for credit is common. The Federal Reserve Banks' 2024 Small Business Credit Survey, with 7,653 responses, found that 37 per cent of small employer firms had applied for a loan, a line of credit or a merchant cash advance in the past 12 months (Federal Reserve Banks). Keep amounts and account details out of the letter.

Dear Mr. Abernathy:

Thank you for approving the equipment loan for Northside Auto Repair.

You asked for a third year of accounts when two would have met the rule. It showed us that our slow winter months were the real risk, and we have changed our plan because of it.

The new lift will be installed in November. I will send you our figures each quarter, as agreed.

Sincerely,

Grace Mbeki
Owner, Northside Auto Repair

For an investor, keep the same shape: thank them for one piece of help, then say when your next update will come.

To a speaker or a volunteer

Speakers and volunteers give time, and there are many of them to thank. AmeriCorps and the US Census Bureau count more than 75.7 million people, or 28.3 per cent of Americans, who formally volunteered through an organization in the year to September 2023 (AmeriCorps).

Dear Dr. Feldman:

Thank you for speaking at our members' breakfast on September 30.

Your story about the first customer you turned away got the whole room talking. Three members told me afterwards that they are rewriting their price lists this month because of it.

We would be glad to have you back in the spring. I will write in January with dates.

With appreciation,

Helen Park
Director, Riverbend Chamber of Commerce

For a volunteer, name the time they gave and one thing that happened because of it. For donors, see our handwritten donor thank-you notes.

Why does a thank-you letter matter to a business?

Because keeping a customer, a supplier or a partner costs far less than finding a new one, and thanks makes people more willing to help again. A letter costs a stamp and a little time. The relationship it protects took far longer to build.

Harvard Business Review reports that acquiring a new customer is anywhere from five to 25 times more expensive than keeping an existing one. It also cites Bain & Company research by Frederick Reichheld, which found that raising customer retention by 5 per cent raises profits by 25 to 95 per cent (HBR).

Thanks changes what people do next. In a study by Adam Grant and Francesca Gino, 66 per cent of people who received a written thank-you helped again when asked, against 32 per cent of those who got a plain reply with no thanks. When a director thanked a team of university fundraisers in person, their calls rose by more than 50 per cent that week (Harvard Gazette).

Should a business thank-you letter be typed or handwritten?

Type the letter and sign it by hand. A full page of handwriting is hard to read and hard to file. The signature is the personal part, which is why the format leaves room for it. For a short thank-you of four or five lines, skip the letter and write the whole thing by hand on a card.

Handwriting does real work on a short note. In a field experiment at an online retailer, Sanghwa Kim, Jeonghye Choi and Seung Hyun Kim found that a handwritten note had a positive and significant effect on what customers went on to spend. The effect showed up with loyal customers, not with others (Journal of Interactive Marketing).

That short card is the part MailMyCard does. You type the note, and a real pen writes it on a card, in a handwriting style you choose or one built from a sample of your own. It goes out in an addressed envelope, and a CRM can be connected so that a won deal sends one. The For business page explains how.

For the last two lines, our guide on how to sign off a thank-you card lists closings for clients, colleagues and customers.

What should you leave out of a business thank-you letter?

Leave out anything that turns the thank-you into something else: a pitch, an invoice or a request. The reader should finish it feeling thanked, not asked.

• A sales pitch. No new services, no price list, no "while I have you".
• A coupon or a free gift. In the retailer experiment above, adding a giveaway or a discount weakened the effect of the handwritten note.
• A request for a review or a referral. Ask another time. Thanks that ends in a request reads as a setup.
• Amounts and account numbers. Letters get left on desks.
• "Dear Valued Customer" or "To whom it may concern." If you do not know the name, find it before you write.
• A second page. If it runs long, cut.
• An apology. If something went wrong, that needs its own letter. See our customer apology letter examples.

Sources

• Purdue Online Writing Lab, Writing the Basic Business Letter: owl.purdue.edu
• George Mason University Writing Center, Writing Business Letters: writingcenter.gmu.edu
• Kumar, A. and Epley, N. (2018), "Undervaluing Gratitude", Psychological Science, via University of Chicago News
• Microsoft, Work Trend Index Special Report: Breaking down the infinite workday (2025): microsoft.com
• Gallup, "Four in 10 Americans Look Forward to Checking Mail" (2015, 1,010 US adults): news.gallup.com
• Hinge Research Institute, Referral Marketing for Professional Services Firms (523 firms): hingemarketing.com
• Federal Reserve Banks, Small Business Credit Survey: 2025 Report on Employer Firms (2024 survey): fedsmallbusiness.org
• AmeriCorps, "More than 75.7 Million People Volunteered in America, AmeriCorps Reports" (November 2024), via GlobeNewswire
• Gallo, A. (2014), "The Value of Keeping the Right Customers", Harvard Business Review, citing Frederick Reichheld of Bain & Company: hbr.org
• Grant, A. M. and Gino, F. (2010), "A Little Thanks Goes a Long Way", Journal of Personality and Social Psychology, via the Harvard Gazette
• Kim, S., Choi, J. and Kim, S. H. (2022), "Do Handwritten Notes Benefit Online Retailers? A Field Experiment", Journal of Interactive Marketing: doi.org