The Scenario
You are an operations manager. Two hundred client invoices need to go out as physical letters by end of business — DocuPost handles the printing and mailing, and the invoice PDFs are already linked in the 'Invoice Queue' sheet. The one thing standing between you and dispatching the batch is a balance check you promised the finance director you would do before spending anything.
The sheet is ready. The PDFs are linked. You just need to know whether the account has enough runway before you trigger 200 API calls that will draw down the balance.
The bad version:
- Log into the DocuPost dashboard, navigate to the account balance page, and note the current figure.
- Open a calculator, multiply 200 letters by the per-letter cost, and compare the two numbers.
- Decide the balance is fine, go back to the sheet, and start entering recipients — because there is no built-in way to make the balance check gate the send automatically.
- Finish entering recipients. Realize the balance you checked 45 minutes ago was before a separate campaign drew it down. Two dozen letters fail mid-send.
The point was to verify funds before committing. Doing the check manually and then doing the send manually means the gap between the two steps is where errors live.
The Easy Way: One Prompt in SheetXAI
SheetXAI is an AI agent that lives inside your Google Sheet. It can check your DocuPost account balance, evaluate it against a cost threshold, and either dispatch the full mailing or flag the shortfall — all in one operation, with no gap between the check and the send.
Open the SheetXAI sidebar and use this prompt:
Check the DocuPost balance; if it is at least $80 (200 letters at estimated cost), send a letter to each row in the 'Invoice Queue' sheet using the PDF URL in column E; otherwise write 'BALANCE TOO LOW — current: $X' into cell A1.
What You Get
- If the balance clears the threshold, SheetXAI dispatches a DocuPost letter for every row in the 'Invoice Queue' sheet using the PDF URL in column E.
- Each successful dispatch gets "Sent" written into a confirmation column — column F, or whichever you specify.
- Rows that fail get the failure reason written into the same column.
- If the balance does not clear the threshold, nothing is sent. Cell A1 gets a message that reads "BALANCE TOO LOW — current: $X" with the actual balance substituted in, so you know exactly what you are working with when you go to top up the account.
- The entire check-and-send runs atomically from your perspective — no manual handoff between the balance lookup and the dispatch.
What If the Data Is Not Quite Ready
The cost estimate depends on letter type
Some rows in the 'Invoice Queue' are standard single-page letters. Others, marked "Certified" in column G, cost more per piece. You need the balance threshold to account for the mix.
Read the 'Invoice Queue' sheet. Count the rows where column G = 'Certified' and where column G is blank. Estimate total cost at $0.75 per standard letter and $1.20 per certified letter. Check the DocuPost balance: if it covers the estimated total, send each letter using columns A–E for the address and column E for the PDF URL. If not, write 'BALANCE TOO LOW — need $X, have $Y' in cell A1.
Some rows are flagged to hold
Finance placed a hold on 15 accounts — column H says "Hold" for those rows. They should not go out even if the balance clears.
Before sending, filter out any rows in the 'Invoice Queue' sheet where column H = 'Hold'. Check the DocuPost balance against the remaining row count at $0.40 per letter. If sufficient, send a letter to each non-held row using columns A–E and the PDF in column F. Write 'Sent' in column I for dispatched rows, 'HELD' in column I for skipped rows, and the balance-shortfall message in cell A1 if the check fails.
The invoice queue spans this month and last month
New invoices are on the 'May Queue' sheet. A handful of April re-sends are on 'April Retry' — same column structure, same PDF column.
Combine rows from the 'May Queue' sheet and the 'April Retry' sheet. Check the DocuPost balance against the total row count at $0.40 per letter. If the balance covers the total, send a DocuPost letter to every row using columns A–E for the address and column F for the PDF. Write 'Sent' in column G in whichever tab each row came from. If the balance is insufficient, write the shortfall message in cell A1 of both tabs.
Full kill chain — filter holds, estimate by type, check balance, send, flag everything
Read the 'Invoice Queue' sheet. Skip rows where column H = 'Hold'. Count standard rows (column G blank) and certified rows (column G = 'Certified'). Estimate cost at $0.75 standard, $1.20 certified. Get the DocuPost balance. If balance covers the total: send each non-held letter using columns A–E for the address and column F for the PDF, write 'Sent' in column I for successes and the error reason for failures. Write 'HELD' in column I for skipped rows. If balance is insufficient, write 'BALANCE TOO LOW — need $X, have $Y' in cell A1 and send nothing.
One prompt, every condition handled before a single API call goes out.
Try It
Open any Google Sheet where a bulk mailing is waiting on a balance verification — invoice queues, donor appeals, compliance notices — and get the 7-day free trial of SheetXAI to run the check and the send in one step through DocuPost. For the bulk letter workflow without the balance gate, see the bulk letter spoke, or return to the DocuPost hub overview.