Keep a simple invoice register with every invoice's number, customer, amount and due date, check it on a fixed day each week, and send reminders on a set schedule with a way to pay in each one. If you'd rather not do that by hand, you can email each invoice to a tool that reads it and chases it for you, though you'll still need to mark payments in your own spreadsheet.
In this article
The short version
- Homemade invoices don't track due dates, reminders or payments on their own.
- Keep an invoice register with number, customer, amount, due date, status and reminders sent.
- Chase on a fixed schedule and check the bank against the register each week.
- You can email invoices to a tool that reads and chases them, by Bcc or a forwarding rule.
- Payments won't post back to your spreadsheet, so you still mark invoices paid there.
Why chasing slips with homemade invoices
A template in Word, Excel or Google Docs is a perfectly good way to make an invoice. It's free, you control the layout, and for a business sending a handful of invoices a month it does the job. The trouble starts after you press send.
The document doesn't know when it's due, so nothing reminds you when it's late. There's no record of who you've already chased, or when. There's no payment link, so the customer has to copy your bank details by hand, and the payment can arrive with a reference you can't match. And each invoice lives as a separate file, so seeing who owes what means opening them one at a time.
None of that is a reason to give up the template. It just means chasing needs its own system alongside it.
A manual system that works
You can run tidy credit control with nothing more than a spreadsheet. Set up an invoice register with one row per invoice and these columns:
| Column | What to record |
|---|---|
| Invoice number | From one unique sequence, never reused |
| Customer and contact | The person who pays, with their email |
| Issue date and due date | Both as dates, so you can sort and filter |
| Amount | Including any VAT |
| Status | Unpaid, part paid or paid |
| Reminders sent | Date and channel of each one |
| Date paid | Filled in from your bank statement |
Every invoice needs a unique number, so take each new one from the register and not from the last file you saved. Print the due date on the invoice as a date, not just "30 days", and agree payment terms before you start. For business customers, if no date is agreed, a payment becomes late 30 days after the customer gets the invoice or you deliver, whichever is later.
Then pick a reminder schedule and stick to it. A common pattern is a friendly note a few days before the due date, a reminder on the day, and firmer follow-ups at about 7 and 14 days overdue, then a phone call. Add a line to the register each time, so you can tell a customer exactly what you've sent.
Ask customers to use the invoice number as their payment reference, and check the bank against the register on the same day each week. This kind of routine tends to slip when the week gets busy, so it helps to put it in your calendar.
Hand the chasing to software by email
If you'd like to keep making invoices in Word, Excel or Google Docs but stop chasing them yourself, you can send each invoice to a credit control tool by email. The tool reads the invoice, picks up the customer, amount and due date, and follows it up.
Adfin's invoice from email feature works this way. You'll find your dedicated address in Settings, under Invoice settings and then Invoice from email. Add it as a Bcc when you email an invoice, or set up a forwarding rule in Gmail or Outlook. Each invoice is read, can have a payment link added so your customer can pay by card, pay by bank or bank transfer, and goes to Adfin's collection agents, which follow it up until it's paid, within rules you approve.
A few things help it run smoothly:
- send each invoice as a PDF attachment, one invoice per email
- keep the invoice number, customer name, due date and total clearly printed in the same place every time
- use the same customer name on every invoice, so one customer doesn't turn into two
- stop sending your own reminders for invoices the software is chasing, so customers hear from one place
How to keep your records in step
Your spreadsheet won't update itself. Payments taken through the chasing tool aren't posted back into Word, Excel or Google Docs, so you'll still mark invoices paid in your register, from your bank statement or the tool's record of what's been paid. When a customer pays you some other way, such as a transfer to your usual account, mark the invoice as paid in the tool too, so the reminders stop.
If the register keeps growing and the double entry starts to feel like the bigger job, that's usually the point to look at accounting software. Adfin has two-way sync with Xero and QuickBooks, so invoices paid through it are marked paid there automatically.
Related guides
- How to create an invoice from a PDF, spreadsheet or photo
- Chasing invoices from a custom or in-house billing system
- Credit control: a complete guide
- How often should you chase an unpaid invoice?
- Payment reminder email templates for UK businesses
Common questions
Can I chase invoices I make in Word or Excel automatically? Yes. Email each invoice to a credit control tool that reads it and sends the reminders, such as Adfin's invoice from email, which works by Bcc or a forwarding rule.
How do I keep track of unpaid invoices in a spreadsheet? Keep one row per invoice with its number, customer, amount, due date, status, reminders sent and date paid, and check it against your bank each week.
How often should I chase an unpaid invoice? A common schedule is a reminder before the due date, one on the day, and follow-ups at about 7 and 14 days overdue before a phone call.
Will payments update my spreadsheet automatically? No. You'll need to mark invoices paid in your own register, from your bank statement or your payment tool's records.
What if my customer doesn't use the invoice number as a reference? Match by amount and customer name, then ask them to use it next time. A payment link avoids the problem, because each payment is tied to its invoice.
When is a business customer's invoice late if we didn't agree terms? The law treats it as late 30 days after the customer gets the invoice or you deliver, whichever is later.
Sources
- GOV.UK - Invoicing and taking payment from customers: what invoices must include (accurate as of November 2026) https://www.gov.uk/invoicing-and-taking-payment-from-customers/invoices-what-they-must-include
- GOV.UK - Late commercial payments: charging interest and debt recovery (accurate as of November 2026) https://www.gov.uk/late-commercial-payments-interest-debt-recovery
- Adfin - Changelog: product updates (accurate as of November 2026) https://www.adfin.com/resources/changelog
