When we talk to supply chain managers, the sentence "we bought parts from Turkey and had problems" usually hides the same few process mistakes; they are specific not to the country but to the nature of overseas sourcing. Our first-order guide explains the right steps; this article lists the wrong steps and their corrections.
Mistake 1: Sending an RFQ with Incomplete Documents
Sending only a 3D model or a low-resolution PDF "to get a price"; no material, tolerance or quantity information. The supplier either quotes high on assumptions or the process drags on with questions. Fix: STEP + PDF + quantity + documentation expectation in one package; our RFQ guide provides a template.
Mistake 2: Looking Only at Unit Price
Choosing the lowest quote; set-up, certificates, packaging, freight and payment terms are not considered. Extra invoices or out-of-scope documents follow later. Fix: Compare quotes line by line; calculate total cost of ownership. An extremely low quote is a sign of missing scope or inexperience.
Mistake 3: Skipping the Sample Stage
Placing a series order directly to save time. If a dimensional or surface problem appears in the first batch, the whole batch is affected. Fix: 1–5 samples + ballooned drawing + inspection report; the FAI process does not save two weeks but it avoids losing two months.
Mistake 4: Stating Documentation Requirements Afterwards
Saying "we needed a 3.1 certificate and PPAP" after the parts have shipped. Material lot information may not be retrievable retrospectively. Fix: List certificates, inspection reports, FAI/PPAP and coating documents in the RFQ; see them as separate line items in the quote.
Mistake 5: Confusing Incoterms and VAT
Comparing an EXW price with DAP; not knowing who bears import VAT and the customs broker fee; surprise invoices on the first shipment. Fix: Request quotes on a single Incoterm (FCA or DAP); know that import VAT is deductible in your own return and that customs duty is zero with the A.TR. Our Incoterms guide and our A.TR article help.
Mistake 6: Moving All Volume at Once
Closing the existing supplier and giving the entire part family to the new one. The learning curve and initial problems stop the whole line. Fix: Start with 5–10 parts weighted by turnover, pilot batch, then phased transition; keep the second source for the first year.
Mistake 7: Neglecting Revision Management
Telling the supplier by e-mail "we changed this dimension"; the drawing is not updated, nobody knows which revision is in stock. Fix: Revision changes only with an updated drawing and written approval; the fate of the old revision in stock (use/scrap/rework) is decided every time.
Mistake 8: Not Stating a General Tolerance, or Tolerancing Everything Tightly
If there is no general tolerance the supplier assumes one; if ±0.01 is written on every dimension the price doubles. Fix: A realistic general tolerance such as ISO 2768-mK, special tolerances only on functional surfaces; our tolerance selection article explains the balance.
Mistake 9: Not Clarifying the Communication Channel and Contact Person
Purchasing, engineering and quality each write to the supplier separately; contradictory instructions arise. On the supplier side it is also unclear who decides. Fix: One technical and one commercial contact on each side; decisions confirmed in writing (e-mail); a short weekly status call.
Mistake 10: Never Seeing the Supplier
Ordering on the strength of the website and certificate photos; the machine park and measuring room are never verified. Fix: A 45-minute video audit or a day-trip visit; our 15-question checklist guides you.
Mistake 11: Discussing Payment Terms Late
Facing an advance-payment request after the quote is accepted and halting the process. Fix: Write your payment expectation in the RFQ; 30–50% advance on the first order is normal, 30 days net is standard in a regular relationship. Options are in our payment terms article.
Mistake 12: Ignoring Cultural and Time Differences
Not putting public holidays in the plan (two religious holidays a year in Turkey, 4–9 days); always reading a "yes" as "understood and will be done". Fix: Add the supplier's holiday calendar to the annual plan; summarise critical instructions in writing and ask for confirmation; ask questions when in doubt.
Bonus: Skipping the Contract and NDA
Basing purchases of hundreds of thousands of euros a year on e-mail quotes. Fix: A short framework agreement (price validity, quality terms, delivery, payment, IP, disputes); the clauses are in our contract article.
The Common Root of These Mistakes
All twelve mistakes come down to a single cause: managing an overseas supplier like a local supplier. Ambiguities settled locally by phone turn into cost with distance and language difference. The solution is not more control but clearer documents: complete RFQ, written approvals, an explicit document list, phased transition. This discipline makes working with a Turkish supplier as predictable as a local one and makes the cost advantage permanent.
Mistake Prevention Checklist
If you can say "yes" to these 10 questions before the first order, you have prevented most of the mistakes:
- Are STEP, PDF, quantity, material and documentation expectation in one RFQ package?
- Am I comparing quotes on the same Incoterm and the same scope?
- Are samples and an inspection report in the plan?
- Are the general tolerance and critical dimensions clear on the drawing?
- Are payment terms and currency in writing?
- Have I seen the supplier by video or on site?
- Has a single contact been designated on each side?
- Is the revision procedure in writing?
- Am I keeping the existing supplier as a second source for another year?
- Have I aligned the holiday calendar with the delivery schedule?
What to Do After a Mistake?
When a problem occurs, the aim is not to find the culprit but to determine the root cause: was the drawing incomplete, did the supplier not read it, was the measurement method different? A good supplier presents root cause and corrective action in 8D format; the buyer also closes the process gap on its own side. How the first problem is managed determines the long term of the relationship.
Frequently Asked Questions
Which is the most expensive mistake?
Skipping samples and placing a series order; one rejected batch can wipe out all the savings. Second, stating documentation requirements afterwards.
Doesn't a good supplier prevent these mistakes?
An experienced supplier asks about missing information and suggests samples; but responsibility is shared. A supplier not asking questions is also a warning sign.
Is this list only for Turkey?
No; it applies to every country in overseas sourcing. Because the time difference and logistics are short in Turkey, the cost of some mistakes is lower.
How many parts should I start with on the first order?
3–10 parts weighted by turnover, a pilot batch of each; the quantity can be 5–10% of annual volume.
Conclusion
Success in overseas CNC sourcing depends as much on the buyer's process discipline as on the supplier's skill; the buyer who avoids these 12 mistakes realises Turkey's cost and speed advantage from the first order. If you would like to start with a complete RFQ, send your drawings via our quote form; we clarify any open points with you before quoting.
