How Writers Bill Retainers, Per Word, and Per Project

You charge three ways. A content client pays you 2,000 dollars a month on retainer. A trade magazine pays 0.65 dollars a word. A startup hired you to write a landing page for a flat 1,500 dollars. Each one needs an invoice the client can read in ten seconds and pay without emailing you back. The only thing that really changes between them is how you build the line items.

Here is how each one goes, start to paid.

The retainer: one line, same every month

A retainer is the easiest to bill and the easiest to get wrong. The temptation is to itemize everything you did that month to justify the fee. Don't. The client agreed to a flat monthly amount. Listing eleven blog posts and four email drafts invites them to count, compare, and argue the next time the output dips.

Build it as a single line item:

• Description: Content retainer, March 2025
• Quantity: 1
• Rate: 2,000.00

If your agreement names a deliverable count, put it in the description, not in separate lines: "Content retainer, March 2025 (up to 4 posts, 8 emails)." That sets the boundary without turning the invoice into a scorecard. For anything over that cap, add a second line for the extra work at your overflow rate.

The part that saves you time is reuse. The retainer invoice is identical every month except the period and the number. Set your invoice number format once and let it increment so March's invoice is INV-0042 and April's is INV-0043 without you tracking it by hand. If you bill the same amount on the same day each month, a recurring invoice that sends itself removes the step entirely. For a deeper walk-through of keeping a retainer consistent, see billing a freelance retainer the same way every month.

Per word: show the math the client already agreed to

Per-word billing is where clients want to see the arithmetic. They approved a rate and a rough length, and now they want the invoice to match. Give them exactly that.

Use quantity and rate the way they are meant to be used. One line per article:

• Description: "The Case for Slow Software", 1,420 words
• Quantity: 1420
• Rate: 0.65

That gives a line total of 923.00, and the per-word rate is sitting right there if anyone checks. If you wrote three pieces that month, that is three lines, each with its own word count. The subtotal adds up on its own. An AP clerk who has never read your contract can still see where every dollar comes from, which is the whole point.

Watch the rounding. If your word count is final, lock it in before you send. Editing a quantity after the fact creates a new version of the invoice, which is fine, but it is cleaner to count once and send once. If a kill fee or research surcharge applies, make it its own line with a plain description. Buried numbers are what get invoices questioned.

Per project: fixed fee, with the scope on the invoice

A flat project fee is the one clients dispute most, usually because the invoice says 1,500 dollars and nothing else. Months later nobody remembers what that covered. Put the scope on the invoice so the number has context.

For a 1,500 dollar landing page, you have two reasonable ways to structure it. If you want one clean total, use a single line: "Landing page copy, home and pricing sections, 2 rounds of revisions" at 1,500.00. If the project has natural stages, split it so the client sees what they are paying for:

• Landing page copy, draft and structure, 1,000.00
• Revisions, 2 rounds, 500.00

Both total the same. The split version is better when there is any chance the client will ask "what about more revisions?" because the answer is already a line item they can see. Spelling out revision limits on the invoice is the same habit designers use to keep an invoice from being disputed, and it works just as well for copy.

If the project hasn't started yet, send a quote first. A quote with an accept step lets the client type their name to sign off on the scope and the fee before you write a word. When they accept, you turn it into the invoice without rebuilding anything. That accepted quote is also your evidence if the scope creeps.

Sending it: a link beats a PDF for all three

However you built the line items, the send step is the same, and it is where most of your time gets wasted if you are still emailing attachments. In invoicing built for writers and copywriters, you build the invoice, generate a private link, and send that link instead of a file.

The difference shows up when the client's finance side gets involved. The person who hired you rarely pays you. Their accounts payable team needs a PO number and the right billing entity, and on a PDF that means a round of emails and a corrected attachment. On the link, the client adds the PO number and fixes their billing address themselves, you get notified, and you can revert anything that looks wrong. No new file, no re-send. If you want the detail on that, here is how to add a PO number after the invoice was sent.

You keep control of what matters. The rate, the word count, the project fee, the line items themselves, those are yours to edit. The client can't change them on the link. If they think 1,420 words was actually 1,500, they leave a comment and you decide. The invoice moves from Sent to Viewed to Paid, and you can see where it stands without asking.

Pick the line-item structure that fits the pricing model, send the link, and let the client do their own PO and billing work. Build the invoice and copy the structure above for whichever way you got paid this month.