The right frequency depends on the type of work you do. For recurring services like cleaning, maintenance, or consulting, invoice on the first of the month or on a fixed billing cycle. For project-based work, invoice at agreed milestones or monthly for work in progress. For one-time jobs, invoice immediately upon completion.

The common thread is simple. Don’t wait. Every day between finishing the work and sending the invoice is a day you’re financing your customer’s business for free. Delayed invoicing is one of the biggest reasons small businesses run into cash flow problems, and it’s entirely preventable.

For recurring service businesses, pick a billing date and stick to it. The first of the month works well because it’s easy to remember and aligns with how most customers think about expenses. Some businesses prefer the 15th or the last day of the month. The specific date matters less than consistency. When your customers expect an invoice on a predictable schedule, they budget for it and pay faster.

If you do project work, establish payment milestones before the job starts. A 50% deposit up front with the balance due on completion is common for smaller jobs. Larger projects should have multiple billing points tied to deliverables or phases of work. Never wait until a project is fully complete to send your first invoice. If the project takes three months, you should have billed at least twice before the final invoice goes out.

For work in progress that doesn’t have clean milestones, bill monthly. At the end of each month, invoice for all work performed during that period. This keeps your receivables current and avoids the ugly surprise of sending one massive invoice that your customer wasn’t expecting.

Payment terms matter too. Net 30 is standard, but if you’re a small business working with other small businesses, Net 15 or even due on receipt can be appropriate. Long payment terms combined with late invoicing can mean you don’t see money for 60 or 90 days after doing the work. That gap is where cash crunches come from.

Automating your invoicing removes the biggest obstacle, which is simply remembering to do it. QuickBooks and most accounting platforms let you create recurring invoices that go out automatically on a set date. For project work, build invoicing into your workflow so it happens as part of closing out each phase rather than as an afterthought weeks later.

Finally, sending invoices is only half the job. Track your accounts receivable weekly so you know who owes you and how long it’s been outstanding. If you’re not following up on overdue invoices within a few days of the due date, you’re leaving money on the table. Many of our clients at M&H Accounting Services find that just getting on a consistent invoicing schedule and following up on aging receivables makes a noticeable difference in their cash position within the first month or two.