批准 estimación 并以 CFDI 形式开票

Record what was executed against each concepto for the period as a percentage of its contract quantity. The earned quantity follows from that percentage and the design quantity, and the earned amount from the same percentage and the position total, so one honest number per line produces the whole valuation.

原因: An estimacion built from a single project percentage cannot be checked and therefore cannot be approved without a conversation. Measured line by line, the disagreement is about one concepto rather than about the whole month, and the rest of the money moves while that one is settled.

Read the valuation back against the bill and check the rates it used are the contract rates. Where a concepto has been measured past the quantity the contract carries, deal with it as a change to the position with an order behind it rather than as a larger figure on the same line.

原因: A concepto extraordinario certified quietly is one the client can refuse at the final account, months after the work was built and paid for down the chain. Raising it as a change while it is small is the only version of that conversation where you are not asking to be paid for work already done.

Take the cumulative valuation, subtract what has already been certified, and apply fondo de garantia at the contract percentage. The figure that leaves this step is the one the CFDI is raised for, and the backup behind it is the measure that produced it. The anticipo is amortised on the same proportion the period earned, so an estimacion that measures more also repays more. Left to a fixed monthly figure it finishes the works still owing, and the last estimacion is the one that discovers it.

原因: Interim payments are cumulative, so the month's money is a difference between two totals rather than a total of its own. Computing it from the cumulative figure is what stops a line being paid twice or dropped entirely when a period is re-measured.

Route the estimacion to the residente de obra, and to whoever the contract adds after them. Keep the approval date, because the CFDI follows the approval and the payment clock runs from there, so an approval that slips moves everything behind it.

原因: Approval sitting in an inbox is the most common reason a payment is late, and it is invisible while it is happening because nobody has refused anything. A route with a date on each hop turns that into a question with an owner instead of a monthly complaint.

Raise the CFDI against the approved estimacion, carrying fondo de garantia and any deduction the contract provides for, and reference the estimacion on it. A stamped CFDI is corrected by cancelling it and issuing another, not by editing it, so the figure has to be right before it is stamped rather than after.

原因: A demand for a figure nobody approved is one that will be returned, and the clock does not start on a returned document. Matching it to the estimacion also means the accounts and the valuation tell the same story at year end without anybody reconciling them by hand.

Open a clock over the CFDI starting from the authorisation of the estimacion, under the public works payment rules. Payment falls due 20 days later, and the clock records that date rather than leaving it to be worked out when somebody asks.

原因: The single most expensive mistake in interim payment is starting the count on the wrong event, because every deadline behind it inherits the error and none of them look wrong. Anchoring on the authorisation of the estimacion once makes the whole chain checkable.

Put the approved figure next to the figure you asked for and carry the difference forward. What is unpaid, and how long it has been unpaid, belongs in the accounts as a number rather than in a conversation.

原因: The gap between applied and certified is the health of the commercial relationship expressed as money, and it is only visible if somebody puts the two numbers side by side every period. Cumulatively it is also the single best predictor of a final account fight.