Mail merge takes a list in Excel and produces one personalised document per row: offer letters, payment reminders, certificates, address labels or emails. It is built into Word and needs no code.

1. Prepare the Excel list

• One header row with simple names: FirstName, Email, Amount, DueDate. No merged cells, no blank rows.
• Keep the data on the first sheet or in a named table — Word finds it faster.
• Save and close the workbook before connecting.

2. Connect Word to the list

1. In Word: Mailings → Start Mail Merge → Letters (or E-mail Messages / Labels).
2. Select Recipients → Use an Existing List → choose the workbook and the sheet.
3. Edit Recipient List lets you tick/untick rows or filter (e.g. only Amount > 0).

3. Insert merge fields

Write the letter and use Insert Merge Field where personal data goes: “Dear «FirstName», your balance of «Amount» is due on «DueDate».” Click Preview Results to flip through real rows.

4. Fix numbers and dates (the part everyone gets wrong)

Word often shows 12500.5 as 12500.499999 or a date as 3/15/2025. Add a format switch to the field: press Alt+F9 to show field codes and edit them:

{ MERGEFIELD Amount \# "#,##0.00" }
{ MERGEFIELD DueDate \@ "dd MMMM yyyy" }

Press Alt+F9 again to hide the codes and F9 to update. Now amounts show as 12,500.50 and dates as 15 March 2025.

5. Finish

• Finish & Merge → Edit Individual Documents creates one Word file with all letters — check it before printing.
• Send E-mail Messages sends through Outlook: pick the Email column and a subject line. (It sends plain messages without attachments; for attachments see sending emails from Excel with VBA.)
• Save as PDF per recipient needs a macro or the newer “Save as individual PDFs” options in some Word versions.

Try it yourself: step by step

1. Download recipients.xlsx and letter-template.docx, save both in one folder and close the workbook.
2. Open the Word template → Mailings → Start Mail Merge → Letters → Select Recipients → Use an Existing List → recipients.xlsx → sheet Recipients.
3. Select the placeholder «FirstName», then Insert Merge Field → FirstName. Repeat for every «…» placeholder.
4. Click Preview Results: Asha’s amount shows many decimals and the date is in US format — the problem the article fixes.
5. Press Alt+F9, add \# "#,##0.00" to the Amount field and \@ "dd MMMM yyyy" to DueDate, press Alt+F9 then F9.
6. Finish & Merge → Edit Individual Documents → you get six letters in one document.