Thanks, however I know how to create a GEDCOM file from Ancestry - but not clear as how to download it on this site. Not clear as to where to find button to import and download on FamilySearch site.
I also have my tree f 15,000 + people backed-up in Family Tree Maker which can be linked to FamilySearch. Can i bring it into FamilySearch from there, perhaps easier?
Not quite sure about your "download" terminology here, but
1) You can NOT download GEDCOM files from the FamilySearch FamilyTree to anyplace.
2) You CAN download FSFT data directly from FS to some third party tools such as Ancestral Quest and RootsMagic.
3) You CAN transfer records and data directly from the FSFT into special church member accounts on some websites such as Ancestry.com or MyHeritage.com
4) You can NOT directly upload a GEDCOM file into the FSFT. However,
5) You CAN directly upload a GEDCOM file into the Genealogies database in FamilySearch. From there it can be searched by anyone, it cannot be modified by anyone (including yourself), and it can have records from it added to or used to modify existing records in FSFT via the GEDCOM compare tool.
6) You CAN upload records and data directly to the FSFT from third party applications such as Ancestral Quest and RootsMagic.
7) You CAN transfer data and records directly from church member accounts on some websites such as Ancestry.com or MyHeritage.com* to the FSFT
I hope that one of the above scenarios answers your question 😊
*Transferring data and records from MyHeritage.com to the FSFT is only done via a sync operation and has several designed-in limitations.
I think Family Tree Maker can read info from FamilySearch, but cannot update back into FamilySearch.
Re: your tree in Family Tree Maker having 15,000 plus people in it, if you were to upload a GEDCOM file of all those records to FS and then attempt to load them into the tree, don't be surprised to discover that anywhere from 9,000 to 13,000 of those names are ALREADY in the FSFT. And if you add them all anyway, you are going to have a massive cleanup job when you have to go through and take all the duplicates out again one by one.
And if you do not have documentation and sources justifying each change that you've made to the FSFT from your GEDCOM file, there will be many people who will come and likely want to undo the work you did.
The GEDCOM upload capability in FS is not intended for a person to dump their entire tree into the database. There is only one tree in the FSFT database and that is the one owned by FS and shared by everyone else here. No one has their own "personal trees" in FS.
The GEDCOM upload and compare tools are for COMPARING records in your GEDCOM file with those in the FSFT in order to see if the FSFT should be updated in any way based on your information. But you will still need to basically go through one at a time to determine what needs to be done with each record.
This tool can be easily abused causing others a lot of grief so please be careful.