хувийн ажил дээр цаг тухайд нь төлбөр авах

Record the contract with its price, its payment terms and the milestones that trigger a payment, so what is owed and when is a property of the job rather than a thing two people recall differently.

Яагаад: A milestone that was never written down cannot be billed without a discussion, and the discussion always happens when you need the money. Written up front, the same milestone is an invoice trigger nobody has to justify.

Raise the payment claim against the milestone as it completes, with the date it went out. Billing late shortens nothing except your own runway, and the submission date is what every subsequent question turns on.

Яагаад: The statutory clock starts from an event, and on private work that event is usually your claim arriving. A claim you sat on for two weeks is two weeks of interest you will never see, and it is the one part of the timeline entirely within your control.

Pick the prompt payment regime that governs this job, by state and by whether the work is public or private, and start the clock from the claim. The due date is then computed from the statute rather than assumed from habit.

Яагаад: The periods are genuinely different between states and between public and private work, which is exactly why people guess and guess wrong. Naming the regime turns the due date into something checkable, and it means the same job billed in another state does not quietly inherit the wrong deadline.

Once the due date passes, the interest the regime provides accrues on the unpaid amount and is calculated rather than estimated, so a reminder can carry a figure instead of a complaint.

Яагаад: Asking to be paid is awkward and easy to defer. Sending a number that grows on a schedule the law set is neither, and it changes what the other side is deciding: not whether to be fair to you, but whether delay is now costing them more than paying.

Reconcile what was billed against what arrived, and keep the ageing rather than clearing it from memory once the money lands.

Яагаад: A client who pays a month late every time is a financing cost you are carrying without pricing it. Once that is visible per client rather than felt in general, it becomes something you can price into the next bid or decline.