Help! What happens if I dont put enough Postage on parcel?

[KDPunshon]

New to eBay.  I have 3 parcels to send now and I think i may have undercharged on the Postage because of the way eBay does the postage.  I dont have a weigh machine as this isnt my business.  When i take the parcels to the post office for 2nd class mail and the postage i paid eBay for isnt enough what will happen?

Thank you for your help.

KD

[sharpiemarker]

They either reject the package, or tell them what you paid online and pay the difference at the counter.  They'll just add an extra postage paid sticker on it.  Are you in the US?   I don't recall the US Postal service having second class mail service.  

If they reject the packages, just get the exact weight for each pkg, write it on the boxes.  Take them home, void all the labels and make new ones with the exact weight, attach and bring em back to the PO.

[KDPunshon]

Sorry, i should have been more precise.  I am in the UK.  The scenario is this:  eBay has suggested 2.80 for the parcel so i pay that and stick the label on the parcel and take to the post office.  The person who has made the purchase of my item has now paid 2.80 along with the price of the item.  I then find out at the post office that i have undercharged postage of lets say 5.00.  I am presuming this is now my responsibility to pay the difference?  I know this seems silly to those experienced in these matters but i am not and so i took it that eBay had made some suggestion of the postage required based on some criteria and I didnt check that out BEFORE the individual made the purchase. 

I have 3 items that i may have undercharged postage for like this so it will be an expensive lesson especially because i have sold all items less than they were really worth and at least wanted to cover the postage.

But now that the person has paid for the item AND the postage and I have printed off the mailing label provided by eBay am I just whooped to regain the difference in postage?  Thanks for your assistance.

[DPCreations]

First, you can't get more money from the buyer for your postage error.  That is just part of your business expense.

Second, best to take the parcels to the local post office and let them add the correct postage or other solution which they have.  There will be significant costs because your online postage price will not apply.

Third, you could void the current label if it is not too late and print a correct one.

[sharpiemarker]

Or go to the PO first to get the weight of the boxes to enter the correct weight then pay for the postage and print the postage labels.