Opsliy

Learn

Blog

Notes on building Opsliy, and on the small paperwork problems it keeps running into.

20 Aug 2026

The eleven documents a small business needs

A short tour of the paperwork that actually comes up, and which document belongs at which moment.

18 Aug 2026

Putting a QR code on your invoice

A payment link your customer can scan instead of typing an account number.

15 Aug 2026

Making an invoice on your phone

Billing from the job, before you forget, without installing anything.

12 Aug 2026

Invoicing a client in another currency

Which currency to bill in, who absorbs the bank charges, and the fields that stop a payment going astray.

8 Aug 2026

Printable invoices you can fill in by hand

For the jobs where a laptop is not coming out of the van, and paper still wins.

6 Aug 2026

Invoicing for tradespeople

Parts and labour on separate lines, callout fees that do not surprise anyone, and billing before you leave the job.

5 Aug 2026

Invoicing for photographers

Day rates, usage licences, expenses and the deposit that protects a booked date.

4 Aug 2026

Billing a retainer without losing track

The same amount every month is the easiest thing to bill and the easiest thing to forget.

3 Aug 2026

Invoicing for cleaning businesses

Regular visits, one-off deep cleans and materials, billed so nobody has to work out what they are paying for.

1 Aug 2026

Invoicing when it is a side business

You have a job, you have a few customers, and you need paperwork that takes minutes rather than an evening.

30 Jul 2026

Setting up your paperwork on day one

Thirty minutes now saves the scramble in month three, when a customer asks for something you never set up.

28 Jul 2026

Deposits and staged payments

How to ask for money up front without it feeling like distrust, and how to document it so nothing gets lost.

25 Jul 2026

Payment terms, explained

What Net 30 actually means, which terms to offer, and why a date beats a period every time.

22 Jul 2026

When an invoice is disputed

A customer says the bill is wrong. Here is how to work out whether it is, and how to fix it on paper either way.

19 Jul 2026

Turning a quote into an invoice

The job is done and the quote was accepted. Getting from one document to the other should take two minutes, not twenty.

16 Jul 2026

Paperwork for returns

Goods come back more often than anyone plans for. Three documents keep it from turning into an argument about who has what.

13 Jul 2026

Custom labels on your documents

Every heading on the sheet is editable. Change the ones that do not match your trade, save once, and the vocabulary is yours.

10 Jul 2026

Invoicing without an internet connection

A basement, a rural site, a plane. The work still happened, and the paperwork should not have to wait for a signal.

7 Jul 2026

Organising your invoice files

Nothing is stored for you, so the folder on your own machine is the whole record. It is worth ten minutes of structure.

4 Jul 2026

Adding your logo to an invoice

A logo makes a document look like it came from a business. It also prints badly more often than anything else on the page.

1 Jul 2026

How long to keep your invoices

Longer than you think, and the obligation is yours rather than any software's. Here is what to keep and in what form.

28 Jun 2026

A ten minute invoicing routine

Most people invoice in a bad hour on a Sunday. A fixed slot on a fixed day turns it into a short, dull, reliable task.

25 Jun 2026

When a free invoice tool is enough

For a great many businesses, a page that makes a correct document is the entire requirement. Here is where that stops being true.

22 Jun 2026

Billing expenses back to a client

Travel, materials, printing, a courier. Recharging costs is easy to get wrong and easy to get right, and the difference is agreeing it first.

19 Jun 2026

When a customer pays the wrong amount

Short by a hundred, over by a thousand, or a round figure that matches nothing. Three situations, three pieces of paper.